Apple hasn't done much in the way of charity efforts overall, but the company was always on good terms with Bono's (PRODUCT) RED effort, through the release of various (PRODUCT) RED iPods.
The charity was started back in 2006 and was meant to help engage the private sector into raising awareness and funds to assist with eliminating AIDS in Africa, the continent most affected by the disease. And it has been a success too - it's raised $150 million+ for HIV/AIDS programs in Africa.
The new bumper for the iPhone 4 and iPhone 4S is priced at $29 and was released this week. Admittedly, its not a huge release but it shows that Apple is still interested in (PRODUCT) RED.
Apple has been applauded by the charity for helping the campaign and raising awareness - Bono even defended the company when it was being slated for a lack of charity help, saying that Apple's participation in RED was "invaluable."
If you want to buy this new bumper, its available on the online Apple store
and will likely be available in-store in a matter of time.
Other products Apple has released to help (PRODUCT) RED were five generations of iPod Nanos (including the latest one), the iPod Shuffle (now stopped) and an iPad smart cover.