I have a solution. My workflow is:
-Import photos into Lightroom from camera to local SSD. Select the option to generate 1:1 previews.
-Edit/trash photos. Publish some to FB, Flickr, Snapfish, whatever I want to do with them.
-Move originals to external storage.
The 1:1 previews stay on the local catalog (they're like.. big JPGs or something). Good enough to show off, even print, but obviously you'd want to edit the originals.
If you're disconnected from that external storage, you can still see the 1:1 previews. If you're connected to storage, Lightroom recognizes it and loads up the originals instead. It's brilliant.
You can even set up a collection that syncs with your phone/tablet. If you're even halfway serious about your photos, lightroom is the way to go.