Nikwax Tent and Gear - Solarproof Spray On Waterproofing and UV Blocker Adds water repellency, increases fabric strength and protects against UV deterioration
Easy-to-use product that can renew/improve the water resistance on existing items. With more coatings, it can make a 'regular' item waterproof as well.
Nikwax products are the best, from waterproofing my ski coat and pants to waterproofing my polarfleece to cleaning my sandles to rejuvenating my old backpacking tent (waterproofing and UV protection) Nikwax is great.