[attempt 5 at posting a reply..if this doesn't work now I'll send you a postcard]
Typing away to someone in an IM while installing software, then boom! The install window pops up asking to do something, and it gets accidentally accepted because I was typing something (argh it just happened while typing this!) and have no idea what I agreed to do or install some toolbar with the program, rawr.
I know what you mean...extremely annoying!