By far my favorite gadget is the Kindle, practically and philosophically--because it goes against a technology trend that scares me.
If you look at online consumption habits, people are being herded more and more toward consuming short and incredibly trivial bursts of information over and over again. Visiting facebook and seeing status updates, Twitter, Digg, etc.
These aren't places you visit for one hour once a day and then leave. You go 100 times a day for 1 minute a time, highly disrupting and distracting other things you could be focused on.
What's great about the Kindle is that it's a hyper convenient gadget that encourages thoughtful reading, where you consume more important content over a longer period of time.
It's a device that seeks to exercise and grow people's attention spans, not destroy it.
(Being in debt I'm getting the most value out of the Kindle by downloading free classics. I'm reading the Sherlock Holmes books now. Allamorph, not the movie, actually indirectly inspired it.)
Why is developing a long attention span good?
-- Often it takes a long time and a lot of stamina to create really great projects
-- People with longer attention spans are more productive
-- ??? I'm sure you can fill in more bullet points in the comments
Also, just to pre-empt, 50% of my reading is done on the Kindle, when I'm at home comfortably, and 50% is done by mooching off the local Borders book store, where I'll go and sit for hours on end reading all their tomes for free. I don't mind reading the "old" way, so long as I don't have to stack my tiny apartment with even more paper.
(Sometimes I'll buy a cappuccino.)
