iPad SAR Levels
The iPhone, for example, has SAR levels ranging from .79 W/kg to 1.38 W/kg, all depending on which model one gets (iPhone 3G is the highest). The Apple iPad on average has an iPad SAR level of 1.04 W/kg. The iPad SAR level varies from frequency to frequency, ranging from .74 to 1.19 W/kg. These are the US FCC levels which are taken over 1g of tissue. The EU levels are going to be similar.
So, if you've been worried about SAR levels, you can rest easy knowing that the Apple iPad is not emitting more RF radiation than a smart phone. Plus, you're not holding the device up to your head either, which is a good thing. The display emits more radiation than a cell phone because of the larger screen, but not more than most notebooks or desktops, but that's a topic for another article.
The long and short of it is that iPad SAR levels are well within the limits allowed by regulatory bodies around the world. I think you would be better served checking the SAR levels of your cell phone since some of the smartphones in particular have levels right at the maximum allowed by the FCC. So, you can keep on downloading those apps and editing your photos on the go with your Apple iPad; SAR levels are, by all current accounts, very safe.