For those who have noticed that the Sonic Sideshow walkabout employs 'carryable' rather than 'wearable' technology Project Miniaturisation documents progress towards a new walkabout rig - an improved sampler program running on a small machine that we can wear.

Alesis IO2 express. 
£99 denmark st. ~ £80 online.  Pretty layout, but would be covered i guess.  Possibly marginally smaller/ lighter? than m audio... would be good to hold one - cop a feel of size and weight.

Behringer U control Uca202.
Small, good. Cheap, good. ~£25-£30. Has 2x2 in/out and a headphone with level control. Think the input levels are all software controlled. Downsides: not balanced inputs I assume,  think its only 16bit. But really easy to mount on the suits- should probly try it. >>>> Ah, no. This looks like a line level only input. Probly back to the drawing board.

Griffin imic.
Ok. Bought one of these. ~£19+ P&P, its small,light,cheap, has a mic level, supposed to be reasonable quality sound, capable of 24bit 48KHz. So heres hoping. Theres some useful Utube tutorial stuff, one of someone using an SM 58 with one, one of digitizing music. 
http://www.macworld.co.uk/digitallifestyle/reviews/index.cfm?reviewid=3262951&productid=3262965&pag

For completeness, Jack also mentioned these:
Alesis MultiMix 6 USB mixer.
~£90 on ebay (also used at good price). Really nice looking little usb mixing desk. (No midi course, also supprised to see it seems to be 16bit). 6 ins on the small one.
http://www.dolphinmusic.co.uk/article/4258-namm-2010-alesis-announces-multimix-6-usb-mixer.html