Why the disparity?
Multiblogger Kevin wonders over at Ten Second News why the disparity exists between Ron Paul's Internet popularity and real-world poll numbers, and partially explains it.
A couple of other reasons I can think of include the undeniable fact that many of the "real-world" polls don't even include Ron Paul. They artificially limit your choices in the primary to Romney, Giuliani, sometimes McCain and/or Thompson, and once in awhile Huckabee. Dr. Paul can't have a very high poll showing if he's not included in the polls, now can he? The "real-world" polls don't seem to be any realer than the virtual polls.
Another reason is that many of Ron Paul's supporters are technogeeks who don't have landlines. Surveys don't call cellphones, so it's not surprising that candidates with less technosavvy supporters are over-represented.