I finally got around to studying the Tibetan script. To help with that I created a Tibetan picker.
This picker includes all the characters in the Unicode Tibetan block.
The default shows all characters as images due to the rarity of Tibetan fonts. Consonants are mostly in a typical articulatory arrangement, with vowels below, and digits in keypad order.
Since characters cover the whole Tibetan block, there are many characters that are used for transcriptions rather than just the characters needed for ordinary Tibetan text. There are also many symbols, and three characters that are not in the Tibetan block itself. I tried to arrange things so that the most commonly used characters for Tibetan or Dzonkha are easy to get at, but I’m open to suggestions.
Note that the Tibetan Machine Uni font I use as a default setting is an OpenType font that requires version 1.453.3665.0 or later of the Uniscribe engine (usp10.dll). So the output is not ideal in my browser. Works fine if you cut and paste into MS Word though. 
Enjoy.
Update:
I installed a later version of uniscribe, and now my Tibetan text looks fine in the browser as well as in Office. On my previous laptop I just used a small tool that’s downloadable from the Tibetan & Himalayan Digital Library. My new laptop, however, didn’t work with that tool – I’ve no idea why. So I had to resort to using the Windows Recovery Console.
I’m already subscribed to Microsoft Volt, so I used the latest uniscribe version from there, dated 4 jan 2006.