I am about to launch a beta site, and heroku looks like a great option. The only think that is getting me down is that the only search option is $20/mth for the Websolr
acts_as_tsearch works great. No configuration needed if you have postgresql > 8.3. Have to experiment with multiple tables though. Will use it on heroku till i can afford the WebSolr Add-on. I found it a better option compared to the texticle method as explained in the article link above (tendermaking).
acts_as_tsearch: http://github.com/pka/acts_as_tsearch