By my fourth night in Chengdu I realized the days were flittering by and I had yet to begin arrangements for my Tibet Tourist Permit (necessary for all visitors) or my train ticket to Lhasa. The former was easy to obtain if you have the time (usually a week), while the latter could be more of a challenge.
I logged onto The Lonely Planet's Thorntree forum for Tibet to see what I could find out. An Israeli in Chengdu two weeks before me spoke of difficulties getting a train ticket. Eventually, the person got a permit, and went to the train station at 4:30am to ensure a train ticket once the office opened. Tickets for the train from Chengdu currently go on sale 5 days in advance, and get grabbed up quickly. This person scored one, and was updating the forum from Lhasa.
On the forum, I also saw positive mentions of Sim's Cozy Guest House. They have a travel desk, and were offering inexpensive permits. I decided I would try my luck with them the next day, which sounded a lot better than queuing at some train station at 4:30am.