Diverse site with "first arrival" maps that date the ruby-throated migration as well as pages for individual hummers, community events, gallery etc.
This is a VERY VERY strong science site.
At least a hundred! hummingbird articles from biology/science publications and a "comprehensive source for information about rare and out of range hummingbirds, with extensive links for hummingbird banding research, hybridization, torpor and energetics, nectar preferences, etc."
The Hummingbird Society
Strong conservation and educational community with membership at individual and corporate levels. Opportunities for Hummingbird supporters from art gallery viewing to wildlife preservation efforts.
Travel with birds:
birdsnetherlands.nl - Tour operator for bird watching in the Netherlands.
(Oostvaarderplassen near Amsterdam).
Green Trail Tours - Indochina
Bird watching tours from 2days to 24 days - Vietnam/Laos/Cambodia
Guided Birdwatching - Global
Bird watching guides for most countries.
Bird Lovers of all kinds...
RollerFeeder - Squirrel Proof Bird Feeder designed with songbirds in mind. This is an ingenious bird feeder. Watch the customer U-Tube video!
http://www.refdesk.com/pets.html - Reference/research source with 20,000 links to wildlife and other animal resources.
San Diego Sierra Club