A simple, streamlined Instapapering tool.
I don't use any bookmarking tools with any regularity other than Instapaper, and I don't need an extension that does anything beyond simply sending articles into the service. This extension aims to make that as simple and streamlined as possible.
The extension has two features:
1) Clicking on the Instapaper icon in the address bar will submit the current tab's URL/Title to Instapaper for later reading (note: it doesn't work properly with Google Reader).
2) Pressing `ctrl-p` (or `alt-p`) on any page has the same effect.
The first time you attempt to submit a URL, a popdown will appear, asking for your Instapaper username and password. As soon as you enter a working pair, the URL will be submitted, and you can move on with your life, reading those long articles sometime later on via the magic of Instapaper.
None of these behaviors is in any way configurable. This is intentional.
If you're looking a less minimal solution, with options and functionality that this extension doesn't provide, check out Instachrome. It's nice, and I learned a lot reading through Edgar's code.
(I doubt this needs to be mentioned, but this extension is ever so unofficial.)
Updated 2010-07-05: Added `alt-p` alias, as `ctrl-p` opens the print dialog in Windows.