I installed some Avid Flak Jacket derailleur and brake cables on my bike today. The rear derailleur cable on my bike requires three separate pieces of the jacket (that means a lot of cutting), but the cable kit came with enough ferrules to do the job. I do not have a cable cutter but I found that a cut-off disk on a high speed rotary tool works extremely well. Results were better than any clipped cable/jacket I've ever seen.
The cables seem to be nice and loosey-goosey! Finally I am able to make some actual adjustments to the derailleurs because unlike the ultra weight-sensitive dolt who installed the cables I replaced, I left enough length on the ends to actually allow some adjustment.
The new cable kits even came with the little nibs to put over the ends of the wires. Very nice!
I bought the cables from PricePoint.com for $20 per kit (best deal I could find anywhere).
TD