I had noticed this some time ago but didn’t think much of it, but a few users are a little upset to discover that their Treos are visible on the Sprint network using Resco Explorer 2008.  They are attributing the visibility to some flaw in the Sprint network.  The “flaw” is not specific to the Sprint network or the Treo.  I can do the same thing on the AT&T network and shortly should be able to verify that I can do it on the T-Mobile network.  Does this pose any security threats?  I don’t know.  I don’t have any services that I know of listening to ports on my phone. If all goes well, I should be able to examine my phone in detail sometime this week to see if anything is listening.