(This is off topic, but I feel it's important to share)
The Red Cross and blood centers do a terrific job of screening blood donations.
As for catching it, you are wrong (I think I might not be clear as to what you mean on the small cut part though) . You can indeed cath HIV, and many other infections, through even a small cut. HIV is passed through bodily fluids, which include sexual fluids, blood (the blood itself is carriers oxygen), and saliva. The universal blood handling procedures mention the use of gloves, because finger tips and around the nails are a common place for open wounds that you don't know of. OSHA even requires gloves to be worn when you handle blood to reduce the chances of catching HIV incase the person that bleed is a carrier, and even has training videos about proper handling procedures. I believe the actual HIV virus can live for up to 2 days outside of the human body. Another import factor is you can be a carrier and not show any symptoms.
http://www.webmd.com/hiv-aids/guide/hiv2?page=1
http://www.webmd.com/hiv-aids/guide/hiv-aids-what-raises-risk
http://www.thebody.com/content/art6073.html
http://www.webmd.com/hiv-aids/tc/Human-Immunodeficiency-Virus-HIV-Infection-Prevention
I recomend you read the articles in the above links. Gays are mentioned as a risk factor, but thier are also many more sexual contacts that are as well.