Certain synthetic oils and partially synthetic oils are actually designed to give you 7,000 to 10,000 miles between oil changes. They cost a little more than regular oil, but are quite worth it in my opinion. Especially if you have a long commute every day. The only thing one has to worry about, if you go with the full synthetic, is that you have to continue using full synthetic oil for the rest of your car's life unless you flush the system.
Was surprised to see this featured. I live not even five miles from where Mercer's is made and sold, so I grew up on Mercer's ice cream. Love, love, love their ice cream! You can even get their wine ice cream on a cone at the store. :)