New and noteworthy for 3/25/09
10 AJAX-based, PHP WebMail Clients For a Great User Experience: This post from the Noupe blog has a nice overview of popular webmail clients, many of which are free and open source. Some support both POP and IMAP, while other such as RoundCube only support IMAP. Most of these clients are straightforward to install on any commonly configured server.
Designing for RSS Feeds: Jonathan Bailey at The Blog Herald has written a useful post covering the problems and solutions of styling RSS feeds, including images, JavaScript and embedding content. There are a wider range of common feed readers in use than browsers. If you care how your content looks when it is presented as a feed, this article is a good place to start.
Web Analytics Tips & Tricks: Tips for Tracking Email Marketing Campaigns: The Google Analytics Blog has good, but brief introduction to tracking email campaigns using Google Analytics. The article covers tags, the link builder and several third party email marketing services that have built in support for Google Analytics.

Widgets & RSS Feeds