There is also a product out there called "FINGER EASE" which is a spray on lubricant for fingertips as well as your strings. It is supposed to even be good for the neck and possibly help prevent fret wear. I've used this some, but very little. However it does work well and helps you slide up and down the neck. Use a small amount though - a little goes a long way, and be careful not to get it on your pick hand as it will give you problems in holding on to your pick. I know that Roy Clark has been known to use this. I suppose baby powder also helps as I know a bass player who used this for his bass. It does leave a little white residue however, but will wipe off.
Joe