Today I created a caching component that allows me to save portions of the website in memory for a period of time. The first area I have chosen to test with my caching component is to cache the right bar data..
When viewing the page for the first time the data is loaded from the database (like normal) but then is inserted into cache for a period of 2 minutes. So for the next two minutes when anyone views your blog your rightbar data will be pulled from cache instead of the database. This is on a per blog site basis.
However, there is a slight drawback to this. Anytime you add a new article or custom links it may take a couple minutes for your new items to show up while the data is cache. At a later time I hope to have it refresh the cache when those types of actions occur.