1/4"/6mm phone jacks are a pain in the rear

[Transmogrifox]

I'm very fond of the BNC idea previously mentioned.  Those are sturdy and easy-to-use connectors.

Another type of connector I have been considering is a small military twist-lock connector:  You could have up to 5 conductors and a shielded ground.  This would allow one to install a balanced output in the guitar along with active electronics.  I have certainly been toying around with this idea for some time, however after having made a few of these cables for one company I worked for I know it's not something you want to do often.  

These connectors also take up almost as much space as the phone jack.

Therefore, I think a BNC typ would be very attractive to me.

I also have been throwing around the idea of using a computer server upright rack with the metal faceplates for DIY FX, since I can mount all my circuits on the back of the plate and simply drill holes for the jacks and pots and make a floor pedal with a bunch of switches on it, driving relays to switch all the FX.

[Hal]

http://www.leonpaul.com/news/big_news_story/igs.htm

fencing connectors :-D

[rubberlips]

Microphone plugs sound the go, low in real estate space, can screw on so they wont come out, can come in 2 and 4 pin (which a shield). Here's the female end you can mount into a box
http://www1.jaycar.com.au/productView.asp?ID=PP2013&CATID=&keywords=microphone&SPECIAL=&form=KEYWORD&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=
Cost more than a 6.5mm plug, but they certainly won't fall out

Or what about F-condectors?

Pete