Dan, your best bet is to join up with the Worldwide Utility News club. They have a dedicated page, as well as a very active list on QTH.net In addition, the hurricane freq lists are just chock full of stuff you can hear with a good receiver and antenna. Check the Utility Listening Wiki on this site. All the links for stuff I've just mentioned, plus more are there. We even have an antennas wiki that can give you lots of ideas on how to build something that might work better than whatever you are using now.
Oh yes, one more thing. The WUN webpage also has newsletters that you can download - you don't need to be a member to access that page. And check out the various ICAO/MWARA frequencies. Again, they have a link on the Utility Listening wiki. Just click on 'wiki' at the toolbar at the top of the page.
73s Mike
[edit] Just made a quick check of this - I don't know if the group still exists, but their webpage is still up - the Michigan Area Radio Enthusiasts (MARE) group may well be right up your alley...
MARE
And MT's top 1000 frequencies has lots of air, marine, ect. Heck, you should have little trouble hearing the various 2 mhz outlets on the Great Lakes, if they still exist. There was a recent MT article, I think, on that very topic....
MT Top 1000 Frequencies
Finally, before it migrates off the server, go to the WUN website and download the Jan 2005 newsletter. That was the last issue Larry Van Horn wrote the Military Lists column, and that's just chock full of good stuff.
WHEW! That oughta keep you busy awhile (hi)