I believe I've released
Tempe 1997 IEM SCK
Anaheim 2005 SCK
Anaheim 2011 SCK
Nuno also released a version of the Anaheim 2011 soundcheck, although his has more static and is missing some of the check. Although he deserves a lot of credit--lord knows I wouldn't have gotten motivated to release mine if he hadn't beaten me to the punch!
There's a lot of sounchecks and some rehearsals out there... I don't remember what all I've got, I'll check it when I'm home. Some Barcelona 2009, Miami 2001, sounchecks of Popmart, Zoo tv shows, The Hague souncheck 1981, Birmingham 1984... those are the most known. Of course quality varies from great to poor sound and some are looseless, some mp3. ..
"Our idea was really to have the audience be on the stage there with you, we learned that in the mid 80s. We've been trying to figure a way to do it outdoors since. There's a bit of sleight of hand involved because by moving all the gear up away from you and over you, you're just left with a little punk rock band there in the middle."
- Bono on the 360 tour