Now while I really don't like people who blatantly "advertise" in my feeback I reckon this is just fine. Something along the lines of...

As a buyer...

Great seller, very pleased! Thanks from CC & GTCC member R-7566
As described, shipped fast! Thanks from CC & GTCC member R-7566

As a seller...

Instant payment, great buyer! Thanks from CC & GTCC member R-7566
Always a great buyer to deal with! Thanks from CC & GTCC member R-7566

80 characters is a lot to get in a nice compliment & a thanks & your member number. I like it a lot Smitty!!!

I do hereby pledge to leave all feedback this way!!!

Cheers, Tim.