I'll just tour my bookmark list, there are probably some good time wasters there. I got a PHD in time wasting, you see...
Kongregate.com? Plenty of flash games there....with achievements. Alot less boring than ''nothing'' and they have really good games. (Some nearing professionnal level) RPGs, too. I'd try ''Monster's Den''. An RPG that could last for several hours.
If you like comics and reading, well...
is my favorite webcomic, and a really good time waster.
A nice browser RPG with TONS of content. Uses a ''turn'' system kinda like the one used here. Great for casual players.
forums supply me with my daily dose of funny, especially ''The Mirth Canal'' which is always full of hilarious links.
Yep. That's my personal cure for boredom.
Might work, might not. But try it, you never know :)