Servers now have icons as part of the 1.8 updates. Since the best changes I've made to Merchant Villages have come from player suggestions, rather than me dusting off Photoshop and throwing some villagers together, I'm going to have a contest. Anyone who'd like to offer a submission simply post it here and I'll chose. Server icons are 64 by 64 bit png files. Use a site such as tinypic to post your submissions in the thread here.