Multi-Twitter is now available for Joomla 2.5!
Abivia's Multi-Twitter module lets you construct complex twitter searches, filter and edit the results, and display them the way you want. Multi-Twitter can perform multiple searches then merge the results into a single feed.
Other Twitter modules simply help you build a search query. Multi-Twitter doesn't. We let you use Twitter search syntax and add value by handling the search results with intelligence!
Here are screen shots of the setup parameters:

This parameter lets you specify the Twitter names of the people you want in the feed. Specify one name per line. You can also add additional search terms to the name, so if, for example you wanted to include @ev, but only if he's talking about travel, you would write "ev travel". If you only wanted to exclude his Tweets about football you would write "ev -football".
From version 1.3 onward, you can remove specific users from the results by putting a dash before the user name.
You can also "trick" the module into doing unnamed searches by using just a dash for the name (make sure you follow the dash with a space). so if you wrote "- journalism", then all tweets that mention journalism would be part of the feed.
If you want to add the same terms to every name in the list, do it here. For example, if you put "joomla OR php" in this parameter, then only tweets that contain either Joomla or PHP will be part of the feed.
This filters search results for Tweets that match the same language code. Note: If a Tweet is retrieved from the user timeline, then there is no language code, so no filtering is possible. Set "Retrieve Timeline" to "never" if you want to use this feature.
When set to no, Tweets directed to an specific person will not appear in the output.
The kill list lets you define terms that won't be included in the feed. Enter one term per line. The Kill List Method specifies how the data in the list will be processed. The default is a case-insensitive match. If you put "Abivia" in this list, then any Tweet containing "Abivia", "abivia", "ABIVIA" (and so on) will be removed. In case sensitive mode, only those matching "Abivia" would be removed. The third mode allows you to use powerful regular expressions.
Entries in the edit list contain two terms, separated by a comma. Thus if you wrote "dick,d*ck", all ocurrances of "dick" in a Tweet will appear as "d*ck". As with the kill list, the Edit List method lets you specify case-sensitive, case-insensitive, or powerful regular expression matches.
Sometimes Twitter doesn't index all that well. This option can serve as a backup. It will request the user's page and scan recent Tweets for matches, adding them to the output.
This is the maximum number of tweets to display.
If set, this option will try to include one tweet from every author in the Twitter Names list. This prevents very active users from flooding out the entire feed. the module includes the most recent qualifying Tweet from each user, then the second most recent, etc. until the maximum count has been reached.
These settings control whether or not author names, references to other Twitter users, and embedded links are treated as links or not.
If set, the user's Twitter image will be displayed.
Now you can display the actual time (relative to the web server time), a Twitter-style relative time, or no time at all.
If Show Time is set to actual, the time will be displayed according to the this parameter.
Actual time is calculated relative to the server's timezone. This value allows you to adjust the time zone. The offset is in hours.
The time limit removes Tweets older than a specified limit. The time can be in seconds, minutes, hours, days, or weeks.
When the Show Time mode is relative, this string lets you change the order of the relative time. %a is a placeholder for "about", %n is the number of seconds / hours / minutes / days, and %u is the units.
This text will be displayed before the first Tweet. HTML is allowed.
This text will be displayed after the last Tweet. HTML is allowed.
This text will be displayed if no matching Tweets are found. HTML is allowed.

Sets the maximum time that the module will wait for a response from Twitter. Note: in some environments this timeout doesn't seem to work.
Limits the number of queries made per page request. If caching is enabled, then the module will cache results from each query individually, requesting more Tweets incrementally on each page request. If you have a large number of users, this will significantly improve load times.