From the Live Mesh blog:

Thank you for using the Live Mesh for Mobile client! For users who saw a fail­ure to add their mobile phone to their mesh, we have deployed an updated build of Live Mesh for Mobile. You will need to down­load the Mobile Installer from http://m.mesh.com/install/wm6/LiveMesh.cab again. Once you have the new installer on your phone, run it and the installed client will be upgraded to the new ver­sion. The new Mobile Live Mesh Client is ver­sion num­ber 0.9.3424.6 (check this through Menu -> About). Now you can start Live Mesh, sign in, and you should be good to go.

Sure enough, I installed it on my Treo this morn­ing, was able to log in and start sync­ing fold­ers. Synced fold­ers can be on inter­nal mem­ory or the stor­age card, and open up in File Explorer when you click on them. Every­thing is editable just like any­thing else on your device. By default Live Mesh syncs your device with the mesh every 30 min­utes, but you can change this if you need to.

My part­ner in crime on Max­i­mum Geek wasn’t so lucky, though. He was told that there were a lim­ited num­ber of allowed users and was unable to reg­is­ter his device with the ser­vice. Now does that mean there’s a lim­ited num­ber of peo­ple who can con­nect at any one time, or that there’s a user cap on this beta? Let me know in the com­ments if you can get it working.

On the whole, very impressed so far. This is going to help enor­mously with NaNoW­riMo, which starts tonight at the stroke of midnight!