Other than quick head shots, I don't really do convention sketches but here's an exception from the 1996 Atlanta Con. You'll never guess who sent me the scan...
X-Men #131 - John Byrne art & cover
2 hours ago
A random collection of material from comic artist Kevin Nowlan. Started with the best of intentions, but like most other efforts, doomed to perish from neglect as soon as the novelty wears off.