Here are some other links to the FAA versions. The advantage of getting them from the FAA, as opposed to a private vendor, is that they will always have the latest revisions - a lot of pilots don't realize that the FARs update throughout the year, just like charts and approach plates (though in reality they don't change that often). Anyway, they should be downloadable, though I've never bothered to try (I have them on CD-Rom from one of those private vendors...

) - hope these links help:
FARs (Electronic Code of Federal Regulations)
AIM
If the FARs are not conveniently downloadable, here's a link to a text version of FAR-61 on the FAA site - you can save this link and then by changing the number at the end from 61 to 91 or 121 or whatever, you can get other FARs in text format as well. I have used this link and it does work.
http://www.faa.gov/avr/AFS/FARS/far-61.txt