I was wondering if there was a way to make a concentrated flavoring from a teabag.  This probably isn't the best choice, but we have teabags readily available in our office breakroom, and I would like to occasionally add flavor to other hot or cold beverages.  Specifically, I sometimes make hot chocolate using steamed milk, and would like to make mint hot chocolate.  Alternatively, I'd like to make some concentrated chai from a chai tea bag and add it to steamed milk. 
When I make iced tea at home, I put 5-6 tea bags in a small pot with about 2 cups of water and let it simmer for a while (usually about 30-45 minutes).  Then I put the concentrate into a 2 quart container and add water.  Sometimes (if I've simmered it too long) it's a little too strong and I'll have to add more water.  Maybe you could try doing that?  It seems like you could even simmer it longer, making it even more concentrated.  Then just bring the concentrate to work and add it as needed. 