Sometimes the old fashion way works out well. Many "old school" rental owners put a sign in their front yard and wait for phone calls. I have seen two lately with a For rent sign in the lawn.
Simply put, when you are in San Carlos next, drive around and look for "rental signs" ...
There is one on Howard a few houses in from Alameda at the present time. I hope everything works out in your search. San Carlos is a wonderful town to call home. All the Best, David Young
Dave Tap Tapper
Craigslist is by far the best resource you can use for rentals. If you are looking for a high end rental, then the MLS might offer some options not on the MLS, but for the vast majority of rentals, Craigslist is it. Right now, the MLS has 6 rentals listed ranging in price from $1675/month to $9800/month - for all bedroom counts.
That being said, there are some tricks to make your search easier. Once you have done your San Carlos specific search on Craigslist, you can copy the URL for that search and save it as one of your tabs in Internet Explorer or Google Chrome (or other browsers, no doubt), and whenever you bring up a new browser window, you will see the latest Craigslist listings.
Hope this helps,