There really isn't a good way to see posts in the past week without specifying a keyword in the search. I agree that the 4 minimum length is pretty limiting. We'll look to see if shortening this will cause too much overhead with database indexes.
For short word searches (Saw, TS, etc...) the Google search works pretty well. To use it, click on Search link and the Google Search is listed there.
I'll keep looking for a better solution. If there is a specific topic you're looking for, let us know and we'll see if we can help find it.
To a small child, the perfect granddad is unafraid of big dogs and fierce storms but absolutely terrified of the word “boo.” – Robert Brault