Although for some strange reason, I never got my census form (very disappointed) -- and therefore couldn't fill it out and send it back on time -- I actually did just finish and e-file my taxes. The down side is the cost. (And what a cost! TurboTax online is nice, but after their purchase and fees requirements, I might have well just saved the ~$100 and done it all by hand.) The up side is that they have your tax information on file so that it makes it so much easier to file the next time around.
Still, you don't have to use an online program (or even an on-your-computer program). Just make sure that you file before April 15.
And if you don't live in the US, then I suppose you don't really have to worry.