When I first learnt about GreaseMonkey and the concept of UserScripts I was quite thrilled at the
endless possibilities. I have created a few simple userscripts at work that saved a lot of time
as the user interface of a central application is not up to the mark and I could easily provide a
seamless navigation by using a userscript. The beauty of a userscript is, there is no need to wait
for the content/application provider to fix a usability issue, the html can be modified on the fly
to make it usable.
Here is a userscript I have written called Permalink Google PageRank Checker. This script identifies all the links on the page that are permalinks (rel='permalink' or rel='bookmark') and
for each of them, displays the pagerank to the right. A good usecase for this is to find out the
page rank of all your blog posts. Below is an example of how this works for WordPress (in the Admin -> Manage section).
The Project Euler Solved In Days user script takes the solved information from the title field and put it in the link name.