-----------------
DON'T stop at the tourist services booth at the Bangkok airport - they provided incorrect information about the embassy and local hotels.
The Myanmar embassy (in Bangkok) is open Monday thru Friday 9:00 to 11:30 and 1:00 to 3:00. If your plane arrives before noon, take a cab directly to the Satthorn Hotel ($8) register and walk to the embassy. You could get your visa the next day (saving $25). It's possible to get an entry visa in one day for $75 ( $50 for 24 hours). Tourist visas are $21 for 28 days, but can't be renewed or extended.
If you're planning on staying at Pa Auk as a lay person I recommend shopping for clothes from Bangkok street vendors - right for the climate and very inexpensive. If you're planning on ordaining, only bring clothes for traveling.
The train from Yangon to Mottama should be the last resort. The tracks are so bad, the train averages under 15 mph. It's like riding a 12 hour roller coaster. The insides of "first class" is filthy and the seats are very uncomfortable.
You will need a zafu and zabuton. I recommend inflateable if you can find them - much less bulky to pack. You can buy pillows here, or bring a favorite . Don't bother with an umbrella - they're big and cheap here.
You can actually buy quite a few things while at the monastery, so don't stress about forgetting stuff. Except earplugs, unless you like listening to roosters crow 16 hours a day.
posted by Brian # 11:20 AM 
