Instapaper
Tools, toys, features, and applications to get content into and out of Instapaper.
Read Later bookmarklet
Drag this bookmark to your Bookmarks Bar. Then simply click it when you're on a page that you want to read later.
A "Saved!" message will briefly appear in the corner of the page.
If you use folders in Instapaper, each folder has a bookmarklet to save pages directly into it under the Folder Tools section in the sidebar.
Instapaper iPhone app
Instapaper's critically acclaimed, award-winning iPhone app is the most popular way to read Instapaper content. View your saved pages in the mobile-optimized Text view. Instapaper is popular among subway commuters and iPod Touch owners because it stores your articles for reading even if you're offline.
Google Reader
Send items directly from Google Reader simply by clicking the Instapaper Read Later bookmarklet with an item selected.
This even works on the mobile, iPhone-friendly Google Reader site.
Instapaper is also an option in the "Send to" menu.