I just started Bitcoin-qt for the first time, and it is syncing. How much space does the blockchain take up? I have my drive heavily partitioned, and my /home partition (linux mint) is only about 20GB. Does anyone have a size accurate within 100MB?
At the moment, it's about 2.6GB, but it will be growing with time.
You can try looking into using an eWallet or some lightweight clients if you are tight on the disc space. Their space requirement is minimal in comparison, but the security model they offer is different. The lightweight clients are developed by other people than the core Bitcoin team, so you have to know that you can trust them (haven't yet heard about a case of the lightweight clients being malicious). With the eWallets you put the security of your money in the hands of the third party and their server. There have been incidents of people losing a lot of coins because of this (like MyBitcoin), but if ran well and by trustworthy people, your Bitcoins can be more secure than on your computer.
Here are the current file sizes:
$ date Thu Jul 5 00:21:12 PDT 2012 $ ls -l blk* -rw------- 1 chris chris 2035532730 Jul 5 00:13 blk0001.dat -rw------- 1 chris chris 699731968 Jul 5 00:13 blkindex.dat $ bitcoind getblockcount 187613
and to give an idea of daily growth, here it is around 25 hours later:
$ date Fri Jul 6 01:33:04 PDT 2012 $ ls -l blk* -rw------- 1 chris chris 2046730806 Jul 6 01:32 blk0001.dat -rw------- 1 chris chris 703234048 Jul 6 01:32 blkindex.dat $ bitcoind getblockcount 187757