Back in my university days, I created this logo for my personal business cards:
Another more recent idea: geometric and simple, fluid curves and a modern flavour (with a hint of Art Deco and the Bauhaus):
But, here is the final logo I will be incorporating into my branding and business cards:
Bold, geometric, and dynamic interplay between positive and negative space - I think this one will work just fine. :)
p.s. Lesson learned: You are your hardest client.