I updated the OP with a requirement I forgot to mention:
- should be a free service/tool useful to the Litecoin community. businesses should just get their own domain.

litecoin.net is shared so that someone creating simple tool like a mining calculator would not have to pay for a their own domain. It is not meant for businesses. Businesses should get their own domain.

That was one of the ideas that I came up with previously. Upside is that it's quicker to release new checkpoints. Downside is that it could cause many different forks if people all have different checkpoints configured. At least with the current way, I know that if you are running 0.6.3c, you will be on the same chain as me.

In the end, I decided to not go through with this idea right now. The solution to a 51% attack is not checkpoints. It's more hashing power. It seems like the threat of an attack has actually galvanized our little community into working together to defend this attack. People have jumped to solo mining in case there was going to be a DDoS of pools. And we saw a lot of miners willing to jump in and help out. Our current network hashrate is at 315 mhash/s. That may be an all time high! So in the end, that's doing a lot more to defend this attack than the checkpoint I added.

Sure I will do that.

hold off on the forum.litecoin.net
I haven't decided what to do with that yet.

I'm announcing that I'm opening up litecoin.net to be used as a shared domain. I think it is beneficial to group all useful Litecoin services/tools under one domain.

This is not a land grab. If you are not providing a useful service or if you currently don't have the service ready yet, I will not approve the subdomain. If it's a work-in-progress, do PM me and I will let you know.
This is first come first served. For example, if you are the first one to provide a mining calculator at calc.litecoin.net, the next mining calculator (even if it's a much better one) will need to use a subdomain that's probably not as easy to remember.

There are 2 special domains (possibly more) that will not be first come first served: forum.litecoin.net and wiki.litecoin.net
Since these will be seen as the "official" forum and wiki, I would need to be sure that I can trust the operators. So if you are interested in operating the "official" forum or wiki, send me a PM.

A few requirements
- should be a Litecoin related site... duh!
- should be a free service/tool useful to the Litecoin community. businesses should just get their own domain.
- should not refer to Litecoin as LiteCoin <- this is my pet peeve
- should not have other altcoin related services/tools because I am not endorsing any other alt chains. Though Bitcoin is ok.
- wallets, exchanges, and pools are not allowed. you should get your own domain. I'm not in a position to deem any site as an official wallet, pool, or exchange.
- basically any site that holds users' litecoins are disallowed mainly due to me not wanting to be held responsible if users lose their litecoins for any reason.
- use a subdomain name that sort of describes your site. for example, I'm not going to approve awesome.litecoin.net no matter how awesome your site is.
- do not claim that your site is the "official" site unless you ok'd it with me.
- do not have excessive ads. I realized that ads are useful to help pay for hosting and such, but if your site is filled with ugly flashing ads, I will not approve it.

So if you have a service/tool that you would like to serve up at *.litecoin.net, sign up here: http://freedns.afraid.org/subdomain/edit.php?edit_domain_id=813116

Here are some I have in mind:

explorer.litecoin.net - block explorer (Someguy123 plans to move abe.liteco.in over)
address.litecoin.net - address tools (Greedi plans to move address.liteco.in over)
calc.litecoin.net - mining calculator
source.litecoin.net - already forwards to GitHub
download.litecoin.net - already forwards to GitHub downloads page
charts.litecoin.net - price, hashrate, pools charts
watch.litecoin.net - something similar to bitcoinwatch.com
faucet.litecoin.net - litecoin faucet
p2pool.litecoin.net - p2pool node
electrum.litecoin.net - Electrum server

Please feel free to discuss projects you have in mind.

Which win32 binary? I just finished building them.

New binaries released:

Windows (zip): https://github.com/downloads/litecoin-project/litecoin/litecoin-0.6.3c-win32.zip
Windows (exe): https://github.com/downloads/litecoin-project/litecoin/litecoin-0.6.3c-win32-setup.exe
Linux (tgz, 32/64-bit): https://github.com/downloads/litecoin-project/litecoin/litecoin-0.6.3c-linux.tar.gz
Mac OS X: https://github.com/downloads/litecoin-project/litecoin/litecoin-0.6.3c-macosx.dmg

New binaries released:

Windows (zip): https://github.com/downloads/litecoin-project/litecoin/litecoin-0.6.3c-win32.zip
Windows (exe): https://github.com/downloads/litecoin-project/litecoin/litecoin-0.6.3c-win32-setup.exe
Linux (tgz, 32/64-bit): https://github.com/downloads/litecoin-project/litecoin/litecoin-0.6.3c-linux.tar.gz
Mac OS X: https://github.com/downloads/litecoin-project/litecoin/litecoin-0.6.3c-macosx.dmg

New binaries released:

Windows (zip): https://github.com/downloads/litecoin-project/litecoin/litecoin-0.6.3c-win32.zip
Windows (exe): https://github.com/downloads/litecoin-project/litecoin/litecoin-0.6.3c-win32-setup.exe
Linux (tgz, 32/64-bit): https://github.com/downloads/litecoin-project/litecoin/litecoin-0.6.3c-linux.tar.gz
Mac OS X: https://github.com/downloads/litecoin-project/litecoin/litecoin-0.6.3c-macosx.dmg

New binaries released:

Windows (zip): https://github.com/downloads/litecoin-project/litecoin/litecoin-0.6.3c-win32.zip
Windows (exe): https://github.com/downloads/litecoin-project/litecoin/litecoin-0.6.3c-win32-setup.exe
Linux (tgz, 32/64-bit): https://github.com/downloads/litecoin-project/litecoin/litecoin-0.6.3c-linux.tar.gz
Mac OS X: https://github.com/downloads/litecoin-project/litecoin/litecoin-0.6.3c-macosx.dmg

Nothing has really changed from the previous release. You may want to build with IPV6 disabled. Please check the build readmes for how to do that.

Mac OS X: https://github.com/downloads/litecoin-project/litecoin/litecoin-0.6.3c-macosx.dmg

Windows binaries coming in a few more hours.

I'll help. Should I bring the chicken or the bbq sauce? :p

You can probably stay on a separate chain. Nodes on the other chain will start banning you because you keep sending them invalid transactions. So you will eventually only be talking to nodes on your chain. But if the pools and exchanges are on the other chain, you may not be able to do much with your coins.

If some people have upgraded and some have not and BCX releases his fork, we will effectively have a forked network. For those that are on the BCX fork that want to switch to my fork, they can delete their block chain and download and run the new client.

If this happens, I will make a post about what to do.

That would suck if BCX's chain overwrote your first mined block. :p

Nope. If BCX indeed forked the chain hours ago, this checkpoint would cause his fork to not be accepted by the people that have upgraded.

The normal defense for a 51% attack is just having more hashpower than the attacker. I do not think BCX can match the current network hashpower, but to play it safe, I'm adding a checkpoint.