Alexaholic is a free service which combines Alexa traffic charts with a lightweight ajax-enhanced interface.

Webmasters, marketers and site owners can compare domain traffic for up to five domains at once, switch traffic chart types and ranges without page loads, and generate report pages that can be easily bookmarked and shared. There is also an option to grab the code for a ?chartlet?, a smaller version of the main graph that you can embed into your site.

Alexaholic Homepage