Identifying Airport and Airport Extreme networks

[Kynan Shook]

OK, I'm currently puzzled about something, and I doubt there's any 
solution, but I'm hoping that maybe somebody knows something that I 
don't.  The basic idea is that I want to know whether I am on an 
802.11b or 802.11g network (Airport versus Airport Extreme, for the 
IEEE-impaired).  It would also be interesting if you could see the 
transmission speed, but I have a feeling that this fluctuates enough 
that this isn't shown anywhere.  Is there any way to tell what type of 
network you are on, without actually checking the base station?
While I'm at it, I can share some knowledge I have on this subject; if 
you know you are on an 802.11b network under OS X, the Airport monitor 
in the menu bar shows you approximately what speed you are running at.  
While 11 Mbps is the fastest theoretical speed, there are other speeds 
(5.5, 2, and 1 Mbps) that are available for when you are further from 
the base station and the signal is weaker.  Four bars in the airport 
menu is approximately 11 Mbps, 3 is 5.5 Mbps, 2 is 2 Mbps, and 1 is 1 
Mbps.  If you want to extend your Airport's range, you can drop the 
multicast rate from the default 2 Mbps to 1 Mbps, although it warns you 
that this may be incompatible with some 3rd party 802.11 hardware.  The 
multicast rate essentially acts as a minimum speed that every computer 
has to maintain.  This is how I first noticed the speed/airport status 
connection; if the multicast rate is set to 2 Mbps, you will never see 
that last nub of a bar lit up alone.  Now, I haven't made sure that 
this connection is still true (and it is only approximate, anyway), but 
I'm sure somebody might find it useful.
Anyway, does anybody know how to identify if you're on an Airport 
Extreme network, or what speed you're running at when on one?