API implementations for read-it-later services: Instapaper and similar

[brentsimmons]

We’ll want to be able to share to Instapaper and similar services.

First step is to figure out what all those services are and list them in a comment below.

Second step is to write implementations for their APIs — but just the part(s) we need to be able to send an article to each of the services.

[Wevah]

The two obvious ones (to me):

• Instapaper
• Pocket