Gay Science Fiction discussion

I thought I'd start a thread to share ways to find gay scifi. Most of us have bemoaned the scarcity, so we should at least know about what there is. Here are my strategies:

(1) Amazon tags. Here is the list for the tag "gay science fiction":
http://www.amazon.com/tag/gay%20scien...
If you look at the tags under a book you like you may see others worth exploring. I have greatly expanded the list of gay time travel books for example. :-)

(2) Our bookshelf here:
http://www.goodreads.com/group/booksh...

(3) Goodreads lists
http://www.goodreads.com/list/show/43...
http://www.goodreads.com/list/show/20...
http://www.goodreads.com/list/show/70...

Any other ideas?

This is a pretty old list (2001) but Lambda Sci Fi (DC Gayalaxians) kept a list of recommended reading:

http://www.lambdascifi.org/books/reco...

All Romance has a tag system similar to Amazon's:

Gay Science Fiction:
https://www.allromanceebooks.com/stor...

Gay Science Fiction Romance (OK - I set that one up):
https://www.allromanceebooks.com/stor...

But the other thing I do is haunt publishers' sites by genre - most publishers of gay and M/M fiction now have SF as a genre selection, or at least a Science Fiction and Fantasy section.