findtweets is a very simple tool find tweet IDs mentioning a given user or the given hashtags. The output is the list of tweet IDs matching the tags or mentioning the user that are newer than the last message sent by this user.
You can download it from here or from github.
findtweets can be used to implement a simple re-tweeting bot by combining it with cron(8) and tweet(1):
* * * * * findtweets -u user -t tag1 -t tag2 | sed -e 's/^/-r /' | \
xargs tweet -u user
Changelog
Version 0.1 (2011-02-16): * Initial version