Is there a way to install Cyanogenmod 7 on the Samsung Infuse 4G?
Although Infuse 4G is not officially supported by CyanogenMod yet, there are quite a few Gingerbread (Android 2.3.x) based ROMs for it available on XDA Developers forums.

An unofficial port of CM7 is currently under development for Infuse 4G.  If you are feeling adventurous, and are somewhat knowledgeable in Linux, you can compile your own version of it from latest sources, as described here.