In reply to Alpenglow:
Are they new Friends with the thumb-loops or the older style technical with the hole?
If the latter, I've replaced a couple of slings that work out alright:
Cut off the old sling, get a 30cm dyneema sling and poke it through so you have 2 loops of equal length and clip them both to a krab. I put a rope retainer on the krab as well with both ends of the sling through so one can never accidentally become unclipped. They hang slightly (~2cm) further down your harness but it doesn't bother me. Only negative is you can't extend by just clipping a quickdraw into the loop, you have to clip a sling into the 'fixed' krab. This isn't a biggie when compared to the old style technical friends. They do however suffer the same problem of the old Friends in that if the krab happens to be right across a nasty edge, there's nothing you can do about it (that's the big advantage of the extendable doubled-up offerings like the new Friends and DMM Dragons).