See my post at https://bitcointalk.org/index.php?topic=436423.msg4809206#msg4809206  Basically, its not worth it to spend money on GPUs for mining.  They just can't pay off their power cost any more.  If you want to start a mining operation to actually turn a profit (maybe) you will need to look at buying ASIC hardware.

You can skim through this post on alt coins https://bitcointalk.org/index.php?topic=199141.0 but there is a lot of speculation.  LTC is fairly well established and there are many sites accepting it and a few exchanges, but really no one can say if one will take off over the other.  If you want to spend some time trading for fun, I would stick with BTC as the trade volume is high enough you can do many trades in a day and there are well established exchanges out there that you know will not just take your coins and run or 'get hacked' and everyone’s money disappears.  Some of the smaller alt coins have such low trade volume it takes a while for buy and sell orders to go through.

What are you using to mine?  If it is just your CPU than that sounds about right, CPU mining is completely worthless at this point.  Even a single GPU will not generate much if any BTC.  If you want to get into mining you will need to spend some time with profitability calculators and decide if its worth it to you to try and invest in dedicated mining hardware.  Otherwise it is a much better use of your money to just buy BTC.  Even if the price never goes up at least you are not burning money on your power bill mining fruitlessly.

If you are asking about how to take the 0.1 you have and somehow earn interest on it there are not really any reliable 'banks' that will just pay you interest to leave your BTC in them.  Your best bet at earning interest on what you already have would be to sign up for a reputable exchange and start playing the market, although that is pretty risky in itself and requires that you follow the price closely.  If you are just trying to store up some BTC as a savings account the easiest way to do that outside of selling some product or service for it is to just buy more of it.

You will waste more power than you will ever generate in BTC.  Even GPUs are practically worthless for mining and can hardly pay their own power bill, not to mention all the heat they generate.  You can get an idea of what your expected hash rate will be here: https://en.bitcoin.it/wiki/Mining_hardware_comparison#CPUs.2FAPUs  It also lists the miner software used and the settings they had for the most part.  You can try some of those miners if they are even still maintained.  ~15 MHash/s for a decent CPU is not worth the effort it takes to get everything installed and running, but if you have nothing but free time and just want to see how it works, go for it.

Hi Iru,

I would suggest before you spend any money that you first spend some time with a profitability calculator (or two, some are better than others) to see if it is even possible to get your money back with the expected difficulty increases.  If you are not getting this stuff for next to free and you don't live somewhere with cheap power I doubt you will ever make your money back in Bitcoin with GPUs.  If you are looking to mine some alt coin you may have a chance to make some money if you happen to choose one that takes off but that is a gamble in itself.  4 GPUs in a single case generate a ton of heat and unless they are water cooled the middle cards will always be heat cycling.  I had 3x6970 MSI lightnings over clocked and had lots of heat problems with the middle card.  Not to mention the box pulled 1kW at the plug while mining.  I shut that miner down at the end of last summer because it could no longer earn enough to pay for its own power bill.

There is a lot of good info at https://en.bitcoin.it/wiki/Mining_hardware_comparison to see what you can expect for hash rate from different cards, although I have found the reported hash rates on there to be on the high side.

Good luck.

If you are in the US, getting USD out of Gox is pretty much pointless.  They have basically distanced themselves from the US market since the whole Dwolla account seizure and then the CoinLab fiasco.  The only way to get your money out in a timely manner is to convert it to BTC and withdraw it.