Orginally posted on my blog as: A hacked emulation of Track to use until Twitter re-enables it and Twitter Track emulation part2 - tracking your own username.

How to use Summize and the DPA to emulate Twitter’s Track feature

Tracking Keywords

1. This builds off the Digital Assistant I orginally documented over on Grinding.be. If you have already done that, skip ahead. Otherwise, go through the steps laid out in Creating your digital personal-assistant; basically just a new Twitter account, populated via a Twitterfeed account.
2. Go to Summize. Enter each keyword you were tracking and get Summize’s RSS Feed for that (it is on the TopRightHand of the screen). Add each RSS feed to the Twitterfeed account you are using to populate your Digital Assistant account.
3. Lastly, just ensure you have SMS notifications turned on when you are heading away from the keyboard; this will also work when IM is fully restored, but Track is not.

Twitterfeed has a minimum poll-rate of thirty minutes, so you still won’t get exactly instant notifications, but it will be close to it.

Tracking your own username

To complete the emulation of Twitter’s Track feature I built this Yahoo!Pipe. 

It gets all the matching tweets from Summize, then filters out any tweets sent by that user.  So you get any replies or references to that user.

How to use: 

1. Enter the username you want to Track, press Run Pipe. 
2. Add the resultant RSS Feed to your Twitterfeed account.
3. Or you can either use Yahoo's email alert option, or if you're in the U.S. use the free Mobile update option. 

Alternate, Simpler Track Solution:

This trades off speed of replies for completeness. 

The previously mentioned Yahoo!Pipe will capture any tweet mentioning your username.

To get just direct replies (the format of which is "@<username> oh hai kthxbai") do the following:

1. copy this string: http://summize.com/search.atom?q=to%3AUSERNAME
2. replace USERNAME with the name of the user to track
3. Add this to your Twitterfeed account.