Techpresident.com has the following comparisons, some of which include alternative and independent presidential candidates (others not included here do not). The original pages have charts showing how these numbers fluctuated throughout the campaign; go to the link and see “charts”. Not all the same candidates were included on each comparison.

Meetup.com members using the site to form offline groups and communities in support of each presidential candidate. (Notes: These numbers include people who have signed up for a topic but did not join a group. Also, Ron Paul is the only Republican candidate with significant numbers; Duncan Hunter became first candidate besides Paul to have Meetup supporters in July 2007, and other candidates soon followed.)

Barack Obama: 14,163
Barr: 5,594
John McCain: 1,398
McKinney: 308
Nader: 293
Mike Gravel: 114

Democratic and Republican candidates’ number of MySpace friends [Note: Since we started charting candidates' MySpace profiles, our policy was to chart the profiles with most friends, official or unofficial. With the advent of MySpace Impact, many official profiles are becoming the most popular, and we have updated our charts to reflect this. For example, Hillary Clinton's official profile has surpassed her unofficial profile.]

Obama: 1,079,192
McCain: 209,781
Nader: 7,843
Barr: 6,034

Facebook supporters
Obama: 3,521,054
McCain: 590,383
Nader: 10,635
Barr: 10,303
McKinney: 4,963

Technorati:

How often the Democratic and Republican candidates for president and vice president, plus the three main third party candidates, are mentioned by name in the blogosphere. Conversations in the “world live web” reflect how interesting a candidate is to bloggers; a candidate may get a lot of mentions for both positive or negative reasons.

Obama: 1,098
Palin: 319
Biden: 99
McCain: 92
Barr: 8
Nader: 4
McKinney: 0

Eventful:

While each campaign is trying to galvanize its support base, something new is happening online: grassroots supporters of the candidates are using a new tool from Eventful.com, an events database, to request, or “demand” in Eventful’s parlance, that the candidate come to their city. So far, only Ron Paul and John Edwards have directly responded to this bottom-up aggregation of voter attention, but several have adopted their Eventful pages. Could this be the first sign of “candidate-relationship management” from below?

Obama: 142,311
McKinney: 434
Barr: 23