Ask Engadget: What are your favorite applications for smartphones and PDAs?

Ask Engadget is back again this week with more questions and answers. Last Thursday reader Taylor R. wanted to know what the must-have gear for business travel was, this week Dan D. asks sort of a general question, but one we think a lot of people will have something to say: What are some of your favorite software apps for smartphones and PDAs? A few of our faves for the Treo are FileZ, Snapper Mail, and Kinoma Player, but which mobile apps have you guys been digging on lately?