Script Summary: You can "Like" all of your selected partner's posts or comments, with a single mouse click.
0. Install Greasemonkey for Firefox. https://addons.mozilla.org/firefox/addon/748
1. Install this script.
2. Login to Facebook.
3. Notice the gray bar on the bottom left of the screen.
4. Select a partner, and like all his/her posts or comments. This works on the partner's own wall as well.