I installed Google Gears shortly after its beta launch a few weeks ago. The only thing I currently use it for is my Google Reader, but I can't help but think that it's missed the point.
The overarching concept is that web applications can be made available even while you're offline. But unless I'm missing something, it requires an active decision from the user in advance of going offline. You click a little green arrow at the top of the site, and hey presto, it goes off and stores a whole bunch of stuff that is needed to present that site to you when you're offline.
But I don't always know when I'm going to be cut off from the internet. Often, I disconnect quickly and unexpectedly (either by choice or technical fault) yet still want to be able to access those applications.
Wouldn't it be better if the activity that ensued when you clicked the green arrow was happening as a matter of course in the background while you're online? Then, when my network connection disappears, I don't miss a beat. I'm simply warned that my information may be a little stale.
Just a thought.
