This is the fifth in a series of forum posts asking for feedback on the software and services around the different categories of Classroom 2.0 programs. This time it's social bookmarking. Del.icio.us, Diigo, Furl, Simpy, or some other?
Which are your favorites and why?
What features are important to you?
(If you're feeling verbose) What are the pros and cons of the programs you've tried?
Hopefully, these discussions will provide an unparalleled reference for new users making choices about what tools to use.