I've also been wasting a bit of time lately. Not really wasting... it does relate some benefit. I found this website called Mac Freeware . Yes, I have a lovely PowerBook G4. It is old. I gave it a gig of RAM this summer, but it's still old and it still has some issues when I ask too much of it.
That said, I downloaded a hell of a lot onto it this past week, and it's now working better than ever.
Just a few of the most useful programs I've found:
Frostwire (like Limewire, but without the bs),
Virtuedesktops (know how Linux Ubuntu has that awesome multi-desktop interface, that spins like a cube? Yeah, that's what this is),
Mainmenu (lets me run maintenance from my desktop),
Quicksilver (a productivity program that lets me call applications out from the depths of my harddrive and tell them to run or print or whatever, just with a few keystrokes. It has many, many other uses even I don't know yet.),
Sidedrawer (a note-taking program that hides on the side of my screen at all times, until I call it out),
Jetphoto (when my computer crashed, they installed Tiger on it for free, which was awesome. Unfortunately, while Panther came with iPhoto, Tiger makes you pay for the feature. Thus, all of this time I have been without a photo organizing program.)
Cooliris (lets you preview the content of a webpage before going there, quick and easy time saver).
Infinite canvas (I actually already had this, but the site has it and it's awesome. It's a very neat little tool for creating interactive, 'infinite' webcomics. Easy and intuitive. I haven't done much with it yet myself, but it's a small and fascinating tool to just have.)
If you have a Mac, take some of these suggestions. I'm amazed by how well my computer is performing. It's even convinced me to keep going with Mac (I was thinking of getting a Linux box next). Good stuff.
Open source software= yay.
I plan on getting a new iMac when I graduate. I'm even thinking of not shelling out for Adobe, but using freeware like Gimp and Inkscapes instead.
We'll see how they work.
Also, check out Splashup. It's like a limited version of photoshop, for free, operating directly through your browser. You can use it on Flikr and Picassa images, or just upload through it to them. Neat stuff.