From my understanding, that's exactly what the SMC Wireless Printer Server allows you to do. In fact, we recently reviewed the product.
Here's brief excerpt that addresses your question:
"With ad hoc mode, you don't need an access point or wireless router. All you need is a bunch of computers with wireless network access cards configured for ad hoc networking. With the wireless network server also set up for ad hoc mode, any properly configured wireless computer within range can send jobs to it."
Here is a link to the full review:
http://www.smallbusinesscomputing.co...le.php/3299911
The section "Improv at the Printer" is probably most relevant to your question.
Hope it helps.
Dan Muse
Executive Editor
internet.com Small Business Channel