Wellcome collection of AIDS posters
The Wellcome Library has a substantial collection of AIDS posters, which they have digitized and launched as part of world AIDS day. You can view a selection on the BBC website, and find out more on the library pages, as well as see a small sample. Perhaps, most usefully, this illustrates the rich holdings of libraries such as these. Their holdings are vast, and just because it seems specialised, doesn't meant that it mightn't have useful material.