Can you capture events from the 5-way keypad of a device using Opera Mini using Javascript? (My guess is the answer is no, but I figured I'd ask anyway)
I'd say no, because Opera says on their dev site that they don't support client side javascript after the page is loaded:
There are a few more caveats specific to Opera Mini 5 that developers need to be aware of: The majority of JavaScript that is triggered onload should work just fine, except in cases where those scripts require asynchronous operations. JavaScript won't run client-side (for instance in response to user interaction) once the page has finished loading. Plug-ins, such as Adobe Flash, are not supported.
Source: Opera Mini 5 specs
Still, Opera Mini does support other Javascript actions, but they all get executed on the server.