The SMH ran an interview with a travel advertising exec today who had a nice tip for remembering your hotel room number:
Carry a marker pen with you when you travel. Write the room number on your room key/swipe card - but to be security conscious, make sure you write it in code. Choose a 9 letter word (like stoneflag) - and assign a letter to each number from 1-9. So room 475 would be NLE.
The article was peppered with eccentric travel tips. I liked this suggestion much better than his other one, which was to carry only 2-3 pairs of undies, wash them in the shower, then roll them in a towel and stomp the moisture out of it. Maybe I'm less practical, but I'd rather just carry more pairs of undies.