i used to be like this too ... i was worried about ruining my cd burner if i burned too much in a day ...
but now i figure ... sometimes running motors (like in a cd drive) for extended periods may even extend its life since they motors aren't sitting around (since motors that sit around for a long time tend not to work later)
i also figure since cd burners are so cheap .. i'm gonna burn as much as i want .. and if it dies, i'll just buy a better, faster one (and probably for cheaper too)
=P