AGWPE (freeware) for APRS message receipt and display.

Setting up the freeware version of SV2AGW's AGWPE (dsp TNC and TNC management layer) involves the following:
1. download the following items:
    d) UI-View32
2. unzip AGWPE to a folder on your computer.
3. create a shortcut on your desktop for easy access to the 'agw packet engine.exe' that you will find in the files you extracted previously.
4. start AGWPE.  you will probably be prompted for firewall permissions to be added, so don't be surprised.
5. if it's the first time, you'll probably be prompted to accept some licensing/disclaimer information before being able to proceed.
6. when AGWPE has started, it will place an icon on your system tray.  If you don't see it, check that windows is not hiding it.  I recommend making adjustments as needed to ensure that it's visible when running.
7. click once on the icon, and you should see a popup menu.  click on 'properties'.  you will then see a dialog where you now click on 'new port'.
8. you should (after being warned about having to restart AGWPE after adding the new port) see a dialog with two tabs, with the 'Tnc Setup' tab being shown.
9. in the 'Tnc Type', choose 'soundcard'.  You'll then be taken to a dialog with a drop-down where you identify which sound-card you want to use for this port.  having made your selection, you are returned to the earlier dialog, where I typically choose 'single port' and then give the port a name that indicates which sound card I selected earlier.  now, hit the 'ok' button.
10.  now, close AGWPE using the system tray icon popup menu's 'exit' option.
11. restart AGWPE.
12. use the AGWPE's popup menu 'SoundCard Tuning Aid' option, and you'll see what the dsp software within AGWPE is observing as audio input.  Now is the time to connect up your radio.  Minimally, if you want to just 'listen', you need to hook up the mic input on the computer to the audio output of your radio.  This is all you need if you just want to listen to APRS messages, which is what I'm focussed on with this example.
13.  watching the SoundCard Tuning Aid window, and, with the option set to 'waveform', adjust the receive level so that when there's a packet coming in, it doesn't exceed the available display area.  note that if you squelch the signal, you'll see a line at the top of the display, and, when a signal is coming in, most of it should be between the two vertical lines.  As a signal is seen, it will appear as a downward representation of the signal.  seems a bit inverted to me, but, that's how it works. ie: instead of the signal starting at the bottom and showing the signal as moving up the display.  In any case, once you've done that, you're probably receiving packets.
14. Unzip the AGWMONITOR zip file, and run the setup.exe program.  This will install the app, and you should find under your Start->All Programs a new option for 'AGWSoft'.  drill into that, and you'll find the AGWMonitor app.  Start it up.
You should now be able to see the packets that are being heard shown on the display of the agwmonitor application.
What now...?  Ok, well, you have a number of options.
UI-VIEW32, UI-POINT32 and Microsoft Mappoint.
I actually use this option, as it was the low cost way to leverage what I already had.  read on:
a. download ui-view32 from as this will listen to the aprs packets the agwpe hears, and take care of organizing the reports into a viewable map. 
Note that there is a registration process involved but this is *very* low cost.  Install ui-view32 and fire it up, and it will immediately start plotting the location of each beaconing station with an icon to represent what kind of station it is, along with the callsign.  This is nice, but, unless you go to a lot of trouble, it does not show you street level detail.
b. I happen to already have microsoft mappoint for use with a gps for street level navigation, so, I was happy to find an app called 'ui-point32' from which essentially leverages mappoint and overlays onto that, the markers for where the various stations are reporting they're located via APRS.
SV2AGW's AGWTracker
George (SV2AGW) has a very interesting pay-ware ($49) app that provides a one-stop app for visualizing where stations are located.
The cool thing about George's app is that it has the ability to use online and offline (ie: internet required versus not) map sources.  His web site shows the following list of map sources for the latest version:
4.Shape ArcView.
5.Garmin .img files.
6.Polish Format.
7.Mapdekode DBX.
8.GPS Exchange Format (GPX).
9.AGW For Poclet PC vector Format. Used by AGWMap PPC.
10.Bing (ex.Virtual Earth Online by Microsoft).
11.Google Online Maps.
12.Yahoo online Maps.
13.OpenStreet online Maps
wow.  that's quite a few.  If you already have any of the above static data available, rather than going the route I did, you may be better served to spend the $49 to get licensed, and use AGWTracker.
Google Earth TRAX (GEtrax)
this is yet another payware tool ($20) that allows you to take AGWPE's aprs packets and get them represented within Google Earth.  It has a 30 day trial period.  This is a nice option if you expect to mostly have an internet connection.
Additionally, with google earth, if you're tricky, you may be able to save the needed tiles or overlay files so that it can still be used while not connected to the internet. But, that's a whole other discussion.
APRSIS32 (here)
APRSIS32 is an interesting (free) APRS app - and note - it's not just a client, it's much more!  It not only can function as a client for AGWPE, but it can also operate as an IGATE (sending reports it hears to the internet accessible APRS-IS databases - from which draws data for display on a web page overlaid on Google Maps), a DIGIPEATER (which re-transmits what it hears so that other stations might get to hear it too if they didn't hear it direct) and can also take NMEA directly from a GPS to get current position information (among other things)....  check out the web site for your self.  You need to become a member of their yahoo group to get access to the download.