I have had some interest in Bitcoins for a few years now. I tested a HD6790 for mining perhaps a year and a half ago (that card mined slowly, but had a relatively high Mh/W rate), but did not pursue it, especially when the value of BTC dropped. It remained in the back of my mind though, and when the value peaked over $200 recently, I thought at the very least, some mining would "discount" the cost of a graphics card. A HD7970 for <$200? Count me in, so I bought one and started mining 24/7. It may actually pay for itself, but likely only barely. Along with a HD7770, it has been steadily mining a little over 0.025 BTC per day.
The first question though, is Why Bitcoins? Some of the earlier comments clearly indicate a lack of understanding as to why anyone would use BTC. Two major reasons are that it is out of the control of any central authority (e.g. a counterfeiter like Ben Bernanke can't simply print BTC), it is anonymous, and it is irreversible (there are no chargebacks). That last point in particular enforces a level of honesty that we might have last known in our grandparents' days. In any case, it is beyond the scope of these comments to cover all of the theory behind Bitcoin (and similar currency), but it is knowledge worth pursuing. A central government could conceivably "take over" the network by obtaining more than 50% of its hash rate, but with the ASIC miners coming online, the odds of that are dwindling.
Remember too, that the Bitcoin network is handling a fractional percent of global economic activity. It is therefor either beneath the parasites' notice, or not of great enough significance to pursue.
In any case, here are some links to more information on BTC in general. Hopefully you will find them interesting.
Good source of information:
http://www.weusecoins.com/en/getting-started
Charts and news articles: http://bitcoinwatch.com/
Lots more charts here: http://www.bitcoinx.com/charts/
Bitcoin forums: https://bitcointalk.org/