A lot of sellers who don't want to run auctions have taken to ending listings manually and cycling through them to relist - I believe there's even a tool on Inkfrog or one of those listing sites (paid) that will do it automatically for those with a higher quantity of listings. New listings get a little boost in visibility for a short while, so it's certainly worth trying listing some items for a couple of weeks, ending them, listing some different items for a couple of weeks, and cycling through the process.
