Some Useful Links:

Orchid Stuff:
Orchid Mall - good for finding plant sources and lots more....
Orchid Photo Encylopedia - very nice reference
Orchid Research Newsletter - a free Kew publication
The Orchid ReSource - provides a nice summary of orchid history (pre 1BC to 1925)
Maxillariinae Phylogenetics - projects the folks at UF are currently working on

General Botany Stuff:
International Plant Names Index (IPNI) - nomenclatural database
Tropicos - Missouri Botanical Garden's nomenclatural database
Tree of Life Web Project
Plant Micromorphology Bibliographic Database - a free service offered by Kew & excellent reference for anatomists
Angiosperm Phylogeny Website - put together by Peter Stevens at MOBOT
World Taxonomist Database
Index Herbariorum - Database put out by NYBG of world herbaria
Index Nominum Genericorum (ING) - another nomenclatural database
Index of Botanical Publications - an excellent resource put out by the folks at Harvard
UF Herbarium (FLAS) - There are LOTS of cool botanical links at this site
Florida Museum of Natural History - museum in which FLAS is housed, on the U.F. campus

Fun Stuff:
mycathatesyou.com - If you like cats, you HAVE to visit this site
XLR8yourMac - This is an excellent Macintosh site with LOTS of helpful information for old and new models
Ani Difranco's homepage - my favorite folk singer