I wouldn't mind walking over to Sabatino's, it's all the way down at the other end of the Harbor though (a few blocks beyond the power plant), and I'm not sure if they're even open lunchtime.
http://maps.google.com/maps?f=q&hl=en&geocode=&q=sabatino%27s+baltimore&sll=37.0625,-95.677068&sspn=64.160835,94.570313&ie=UTF8&ei=OymdRpXrIoWArQK61MWqDA&sig2=9mNr8TIFANIZfw_-HsPLoA&cd=1&cid=39286294,-76601809,9455020473244308944&li=lmd&z=14&t=m
The walk is about 4/5 mile from the convention center, and half a mile from the fountain.