I've used tyre liners in the past, and once fitted they do seem to work, but they do have a weight penalty. Because the weight is on the edge of the wheel it had a noticeable effect on acceleration, and will also slow you down on hills.
Continental do a range of tyres, and some of them have a 12 month anti puncture guarantee.I've used tyres like these for over 3,000 miles, and the only puncture was a piece of curved glass that cut through the sidewall of the tyre (and a few pinch flats because I let the pressure drop too far).
Another thing I've tried is tyre sealant. This did work, and saved me a few punctures while I've been on long rides, but it can be messy, and again, it has a weight penalty.
Personal experience and
· 9 years ago