I love spring. I love new ideas. Here's a few from ClickZ this morning on "new" approaches to e-mail marketing. Remember, nothing is really "new" (well, few things) but if you haven't heard these, they're "new to you"! :) (me too...)
Press releases - and not the boring text crap either, spice it up w/a photo or two and send to current customers
Actionable e-mail templates - some companies use toolbars with buttons for "Request a Brochure" and "Recommend a Colleague."
Interactive quizzes
Graphs, charts, comparisions, matrices - do some work that you're audience will appreciate & showcase it (competitive reviews, lists of ideas w/cross sections of execution methods, publish a survey or the aforementioned quiz results
Top 10 lists - Letterman's been doing it for years, and we all still watch - there must be something to this!
Interview formats - people enjoy reading interviews of well-known people
Q&A formats - write an e-mail in a question-and-answer format, or have an "ask the expert section"