My local bike shop, being the awesome guys they are, decked out my new Venge with Jagwire premium wires and housings which is cool enough but they went the extra mile and installed in-line barrel adjusters for the derailleurs as well:

In-line barrel adjuster

Rocket Adjuster – to show location

Here’s how they bailed me out yesterday toward the end of my 70 mile ride…  We’re on the last eight miles, the babysitter texted me that her son had to bowl at 1 – it was 11:40 so I had just about enough time to make it home if we hammered it.  I was second and just getting ready to take my pull.  I was well rested and prepared to pull hard.  On the way down a hill I up-shifted a couple of times to make the most of the help and I noticed the chain was rubbing on the front derailleur – a lot.  Cable stretch at entirely the wrong time.  I didn’t even have to break cadence, three 1/4 turns on the barrel adjuster right in front of my handlebar and the rubbing was gone.  This saved me until I could get the bike home and adjust the front derailleur properly on the stand.  No stopping, no fuss – and more importantly, no putting up with a chain rubbing on my derailleur cage.

The adjuster for the rear derailleur is the big deal though – you can make needed adjustments to the rear derailleur without having to get off the bike or having to live with a clicking, maladjusted, non-shifting rear derailleur until the next rest stop.

If you’re a do-it-yourself’er they have instructions on the website, however they recommend that the in-line adjusters are not used for the brake lines – which makes sense to me, you don’t want a weak link in the only thing that can stop you.

They’re especially excellent for internally routed cables.