If you just want to dip your toes in the water, you could always start mining. Doesn't take any initial investment or bank information or anything like that, just processing power.
Joining a pool is pretty painless though. You just create an account, and probably give them an email address, and then start running GUIMiner or something. You also give them a Bitcoin address to send the rewards. That's it, no other personal information needed.
Actual math: 0.00000336030223163 BTC per share, I generated 21 shares, so my balance is 0.00007057 BTC. Roughly the amount I quoted, yeah.
If you go with today's exchange rate, the Bitcoins I've collected mining since January are worth between 3 and 5 dollars (US) a day. I only recently shut down my BTC mining to try Litecoin, which is reported to be about 4x more profitable to mine.
The profitability of mining has gone down sharply in this time, if you ignore the fact that the exchange rate over time has made up for this fact. The coins I mined in January were worth more because there were more of them (and I didn't cash them in.) Last clean 11 day sprint of mining before the LTC experiment resulted in 0.2652BTC, same as the 8 day sprints in January.
EDIT: I forgot to mention I have a video card that I bought from Best Buy about a year ago for $160. Not exactly top of the line.