Some I did a while ago: Turboprop version of the Me P.1099 (which was itself a derivative of the Me-262 - it utilised the wings and tail of the Me 262). The plan is that this is would be a carrier based bomber, somewhat similar to the North American AJ Savage:
What if the jets never quite made it - could the Me-262 have been put into service with piston engines?
I think blade tips will be damaged somehow.
How about a Me-262 floatplane?