A while ago I inherited the English-Tibetan dictionary hosted at zanwat.org. I finally got around to getting it updated and online; you can find it at http://www.eng-tib.com/ and also at my website. It has a little over 1600 words but I've been adding to it as I study. Right now it displays the Tibetan in transliteration, but I hope to get it to display in unicode Tibetan.
Anyway, if you or someone you know studies Tibetan pass the word along and maybe it can become a nice resource for everyone.