I have one, however it is just a basic one:
-----
User-agent: *
Allow: /
Disallow: /Application.cfm
Disallow: /swoj.css
-----

It just allows all robots to access the site but not the two files mentioned (why I listed the .css file I can't remember!)

Another useful tool to use to make sure Google finds everything on your site is the Sitemaps feaure of Google. You generate a file that Google checks, in that file you create a list of all the pages in your site and the suggested refresh for the Googlebot.
http://www.google.com/webmasters/sitemaps

I've not set one up yet for Swoj.com, though we do use it for work.

I've also found that having the Google Ads on the site helps as well, anywhere you display an Ad Banner, Google will index the page so that it knows what types of Ads to put on it.

if you go to www.whitehouse.gov/robots.txt they have a MASSIVE one