Spoke Size / Spoke Length Database - What size spokes do I need?

A question for you wheel builders - I've run my hub and rim choices through Lenni's database and it suggests a 295 mm spoke length. I've a box of 298 mm spokes sat here - is it worth risking it or should I get the proper length spokes?

You could use nipple washers to compensate for 1mm of length, and then you should be OK. The washers help you build a better wheel too, by reducing the amount the nipple grips the rim drilling. When I used them I had them standing in a bottle cap of oil, to help matters further.