Nipples are sometimes undervalued. The don't necessarily stick out all of the time, but they can get people excited. Reader Luke from New York likes nipples, spoke nipples.
You definitely do not want any frayed cables on your bike. I can tell you from experience that a frayed cable possesses a unique ability to embed itself deeply into the human epidermis. Luke blogs over at Luke of NY and he used a spoke nipple to serve the purpose of a cable end. The following pictures come from his blog -
Nipple to the rescue! Crimp and go.
In the past I faced a similar problem and a large dollop super glue will also do the trick. Readers feel free to comment on cable security/safety hacks if you have them. You can also contact us via email and we will tell you how to send us text and pictures for posting if you are so inclined.

In the past I've used wire butt connectors (two ends in one piece just cut in half) A small section of I.V. tubing with some JB Weld drawn into it like a straw and molten plastic. The molten plastic had to be the worst thing I ever tried.
Posted by: Raiyn | 01/25/2011 at 02:20 AM
Heatshrink tubing works pretty well, but it's not as durable as metal. Nipples are nice.
Posted by: scarecrow | 01/25/2011 at 05:41 AM
I've used a little bit of electric tape for temporary jobs. Aluminum nipples are a great idea... why didn't I think of that?
But here is one cable hack... when replacing your brake cables with mountain-bike style brake levers, check to see if the first 8 inches of cable from near the lever are any good still. If they are, they make great straddle/yoke cables for some cantilevers.
Posted by: thomas | 01/25/2011 at 07:55 AM
Solder--Do it right and you can still feed the cable through the housing.
Posted by: Grendel | 01/25/2011 at 08:08 AM
Or... you can buy 500 cable end crimps for $18.99 plus shipping at http://www.jensonusa.com/store/product/CA409Z11-Jagwire+Cable+End+Crimps.aspx and be set for many many years (I'm sure there are good deals elsewhere too).
Unless you build wheels a lot, don't know why you'd have lots of spoke nipples sitting around anyway...
Posted by: Matt | 01/25/2011 at 11:14 AM
I used to have a mechanic that did the solder thing, and I highly recommend it! If you're doing it yourself, be careful to use pure silver solder or pipe solder - not standard electronics solder. I found that did not stick.
Posted by: Jeff | 01/25/2011 at 01:54 PM
I'm another supporter of solder.
Posted by: nick | 01/25/2011 at 03:29 PM
BEESWAX!
Posted by: Stuart | 01/26/2011 at 11:21 AM