The Post is doing a great job visualizing the election so far, with a number of clear tools that they are keeping very up to date.

First up: Maps and interactive filtering of spending on ads, including videos of the ads themselves:

A Primary Tracker: mapping out candidate visits, “pre-game analysis”, results by county, and “post-game analysis” – for EACH state!

And a campaign finance explorer:

They also have something called the @MentionMachine that supposedly tracks candidates by twitter mentions and other media references that you can drill down through. Unfortunately, it isn’t working for me on either Firefox or IE.