What 100%, never-pay-a-dime, free till the day you die software and web apps are currently in your repotoire?
Currently, I use gaim for IMing. It has AIM, Yahoo, MSN, ICQ, IRC, and a slew of other chat programs that no one uses, since those are the big ones. It’s not without its problems, though. File transfers under AIM don’t always go smoothly, and the GTK+ runtime enviroment it uses is buggy as Hell (mouseovers are a big problem. Mouseover windows appearing when your cursor is somewhere else entirely.) But when forced between that and the bloated, POS that is the real AIM client, I’ll take gaim anyday.
I use The Gimp for what little graphics manipulation I do. Not as many features as Photoshop, but more then enough for what little I do.
Hipcal is my calendar of choice. It integrates with other things like Outlook and Thunderbird for schedules, contacts, etc…, it sends emails and text message alerts for events, and has groups that can be made so everyone in that group all gets the same alerts, events on their calendar, and so forth. And the best part? It’s desined for Firefox, not IE. Woo!
Foxit is better than Adobe at opening up it’s own PDF files. As long as all you need to do is reawd and not edit, it’s far superior. Only a single, one megabyte exe file. Perfect for anyone that has had system crashes or slowdowns when trying to view PDFs.