For your day-to-day general use, I bet there's a web app out there that will do the job for you and will be, more than likely, free, or at least very cheap compared to traditional desktop apps.
The evidence for this is also backed up by the number of netbooks currently being released, who's primary purpose is to be able to run web apps. The recent announcement of Google Chrome OS is another step in this direction.
So, what do I use? I'll be going into more details about some of the apps I use in later posts, but here's a taster:
- email - gmail
- Word processing, spreadsheets etc - Google Docs
- Task/project management - Remember The Milk
- General note taking and storing of data I'd like to get back to later - Evernote
- Photos - Flickr
- Blogging - Wordpress and Blogger
- Web site stats/monitoring - GetClicky
- Mind Mapping - Mind Meister