How long would it take for a transaction with 0 fees to be confirmed six times? I thought my wallet would ask me for a tx fee, as it always does, it just sent the amount without any tx fee at all. Now it seems to be stuck in some sort of bitcoin limbo. It's been two hours now, and not a single confirmation has happened.
Dont worry about that. If you check blockchain.info at your transaction you will see it has medium-priority, which is the reason why it was send without transaction fees:

https://en.bitcoin.it/wiki/Transaction_fees

I normaly send transactions without fees, it can take some time. For me it was no longer than 6-12 hour until it got included into a block. If it got inlcuded (1 confirmation) it will get confirmed again every block. So after it was included in the chain you only need to wait 60 minutes for you 6 confirmations.

If your transactions need to be send quickly you should add some optional fees on them, which can be set in the options of bitcoin-qt (if that is your wallet).