Specifically, put your business on Google maps. Google has been beta testing local text and image ads on local.google.com for a bit. Check out the details here:

https://adwords.google.com/select/localbusinessads.html

Paying for an ad makes your ad appear as a "sponsored link" and shows a small bit of text about your business. If you don't feel the need to purchase an ad, don't forget to add your business to Google Local. That's free, and it will help people using Google Local to locate your business.

Update 2006/06/20: I stumbled on a good article at SmallBusinessComputing.com that covers this information and more. Read "Google Maps: A Primer for Small Business".