A few of my favorite applications...
Most, if not all, of these applications are free.
As you'll guess from reading this blog, I'm a HUGE fan of open source software in education. In 2009 I created a Free and Open Source Software Disc for students and teachers in our school community. Check out the link to view the titles that I placed on the disk.
On the iPhone:
Barnes and Noble eReader
On my computer:
Google Apps (Docs) - for document creation and collaboraiton
Google Reader - RSS/feed reader
Jing for creating screencasts and annotated scree grabs
Skitch for creating annotated screen grabs
Audacity for audio editing
iMovie for Video Editing
VLC for playing nearly every kind of media file imagineable
I regularly use multiple browsers, including Firefox, Chrome, and Safari. I also have Opera installed on my computer, which I find to be incredibly fast. Unfortunately it doesn't play nicely with a few of the sites that I frequent so I tend not to use it much.
Diigo and Delicious for social bookmarking
Flickr for online photo storage