Twitter Auto-Responder

Anyone know of a free reliable method to auto respond to keyword strings from users posts ?

I used to use a Yahoo Pipes setup which used a Twitter generated RSS feed for a search term then creating an output RSS feed which fed into TwitterFeed with the auto responses.

I'm sure those who have looked into auto responders before know what I'm on about. However ever since Twitter seemingly closed off RSS feeds I've been looking for an alternative method and I'm drawing a blank ?

Any ideas ? Or does anyone know how to get an RSS feed for a specific search string out of Twitter now ?

I've used socialsprout, they had a free membership once upon a time, but I'm unsure now.

Hey thanks for your replys guys.

Yer username RSS feeds are all good and well, but the RSS feed I'd need is for a specific search string. There used to be a RSS feed button top right after every search you made on twitter, but its no more.

Example being the search term of "penny+stock+trading" which would bring up all users using that specific string within there tweet.

It then allowed you to auto respond with a predefined message such as "Hey, Have you checked out mysite, some great penny stock trading tips" etc

Spam at the end of the day, but it worked great. Free traffic from very little work. 5 twitter accounts each with 4 pipes setup against them searching and replying to different strings.

I'll post up if I find a way around this and a tutorial if so.

Just checked out Socialsprout Moosey, dam expensive now days $39 a month after the free trial and thats only for the basic package!