When I want to do this, I just leave my HTPC running the MC Server, and link to it from Gizmo on my Android phone. Works fine, although the search function leaves something to be desired. It works for specific searches.
It would work using Panel as well. Actually, Panel has better search features, if you use simple expressions. i.e. mediasubtype=movie n{ame}=Wonder
"n" is a short Search Keyword for [Name]. I think I shall be adding a Search Keyword of "mst" for mediasubtype, after playing with Panel search features.
I leave the Server running because Wake On LAN doesn't work from outside my LAN, because of my Router. It won't forward the broadcast WOL packets required to wake a PC. But it can port forward a connection from my Phone on the mobile network to the MC Server, allowing me to check which movies I have already.
The only offline solutions I know of would involve exporting a movie list from MC, and then carrying that around with me in some form. It is pretty easy to export the contents of a View and import that into Excel, for example. But I prefer the Gizmo solution. I just have to remember to leave the Server running, which means changing Power settings so it won't sleep.