naps RULE! period
i often have to put up with a lot of restless nights due to my noizey halls and stupid druken flatmates, generally come the next afternoon i'll be feeling like a zombie... so i used to hit the sack for 45mins... but i'd wake up feeling still pretty tired if i was already short on my sleep and like others have said it is hard to sleep at night (i only nap for that long if i'm gonna be out partying the same evening), now i tend to just put my head down for about 15-20mins and it works great, when i get up i don't feel so tired but i'm still pretty 'with it' as i've not been sleeping for too long
i'd rather nap during the day and get a good 7 hours sleep, than sleep for 9-10 hours in one go, i find if i sleep too long i wake up starving! but if i throw in naps instead i can just keep eating every few hours, it definately works gd for me!