This isn't really a tax question, but I'd be interested in the experience with preparing returns on the IRS site -- as opposed to the commercial software?
A few years back I was involved in a state bar association pro bono program which prepared returns for the working poor, trying to keep them out of the clutches of those store-front loan sharks. I was never certain, but I think we may have been using software provided by the IRS, and it seemed reasonably easy to use.