Can I double-spend against myself to fix a transaction sent with no fee?

[chiropteran]

I send several bitcoins from one wallet of mine to another, using the default bitcoin client, version .8.1

The client didn't ask me to include a fee and I didn't think to add one manually.  It's now 2 hours later and the transaction is still sitting at 0 confirmations.  I understand that it may EVENTUALLY go through when some generous pool wins a block and decides to include some 0 fee transactions.  But, isn't it theoretically possible for me to simply double-spend those bitcoin, since they haven't actually be officially spent, and send the same transaction again, with a fee?

I just can't seem to figure out any way to fool the regular client into letting me do this.  I'm a little bit afraid to go searching google for a hacked client that will allow double-spending, because it sounds like the exact sort of program favored for planting trojan infections.

Is there a possibility of doing what I want?  Is there a legit tool or utility I can use to try to double-spend my coins?  Or do I just need to wait it out, and get my coins when they come?

[jackjack]

Wait 24 hours it should be included eventually
If it really bothers you, you can try pywallet
Afaik no client allows double spending

[DannyHamilton]

I don't know of any trusted client that assists you in intentionally creating a double-spend.

If you know what you're doing, you can create a double-spend raw transaction, sign it, and then broadcast it.

The tricky part will be getting peers to accept and relay the double-spend so it will get to a miner.

If you shut off your client for a few days, the network will forget your transaction if it hasn't made it into a block yet.  Then the peers will relay the double-spend.

[john_doe]

Don't worry, it *will* go through... eventually