Even if you choose text links, Google's only option for you is Javascript Code which limits the way you can promote their programs. Is there any way to figure out what your affiliate URL is? I'm interested in promoting their Adsense, Adwords, and Firefox program.
I don't think you would be able to use them on their own if you found out what they were. As to Adsense TOS you can not modify any of their code.
I honestly think they should change those rules because it limits what their affiliates can do. If I'm correct, Commission Junction was going to replace their HTML coding with strictly Javascript but later changed their minds.