espn and various draft specific sites do exist:
good site, lots of mocks, mainly first rounds, lots of positional rankings and scouting info
http://football.about.com/cs/nfldraf..._mockdraft.htm
lists TONS of mocks (including one into 3 rounds by CDS), has forums etc
http://www.footballsfuture.com/2006/mock.html
very complete player info and also tons of mocks:
http://www.fftoolbox.com/nfl_draft/2006_profiles.cfm
of course espn has a site, not nearly as extensive, but generally viewed as more authoritive (mel kiper and all):
http://sports.espn.go.com/nfl/draft06/index
cbs has a bunch of crap too, about on par with espn...