My current (low) goal is to write at least 1,000 words a week. I put 10 paperclips on a sticky note titled "not yet written" and made another sticky note titled, "written!" Each paperclip is worth 100 words, so 10 paperclips=1,000 words.
Every time I write 100 words I get to move a paperclip from one sticky note to the other. This gives me a visual representation of my progress while I watch the unwritten pile shrink and the written pile grow. This is the first week I've tried it, so I'll be sure to come back and let you know how it worked for me.
If it works especially well, I'm thinking of doing a bigger version. Maybe two small jars and 80 marbles, representing the 80,000 total words I'm shooting for in my manuscript?
Update: I've used the method once now and it worked pretty well! I didn't usually notice when I passed 100, and when I did notice I often got to move several clips at once, which was a nice boost.