I recently had a chance to visit the new GLBT Museum in San Francisco, and it was pretty much a homo history nerd's dream come true. It's billed as the "first full-scale, stand-alone museum of its kind in the United States", and it serves as a welcoming and accessible showcase for the GLBT Historical Society's archives. The museum occupies a storefront in the Castro neighbourhood and thus isn't that big, but they've managed to display an impressive range of artifacts (including Harvey Milk's kitchen table and megaphone, Del Martin and Phyllis Lyon's wedding suits, zines, matchbooks, banners, oral history recordings and an ancient vibrator that haunts me still). Full without feeling crowded, the gallery space also features several text panels describing the city's queer history and the ways that it has been shaped by race, class and gender. Even if you aren't planning a trip to San Francisco in the near future, you can find several online exhibits linked from the Museum's site.
*Note to prospective donors: the CLGA has more than enough material to create a similar museum documenting queer Canadians' unique experiences...just sayin'.