Sad but true. Often, I find that it helps to open a new window for things that I need to read, fill out, etc., because 1), it makes it harder to be distracted by the "fun" tabs I also have open, and 2), Firefox (at least) can't save all of your tabs when you have two windows open, so you have to close one of them, and the "serious" window is a way to force yourself to finish everything in that window before you close your browser and do something else.

Having said that, LW usually takes up most of my saved "fun" tabs...