In reply to JamButty:
I have had one of these for at least 15 years, although it was branded differently:
http://www.giyo.com.tw/web/02mini/GP-01.htm
It was cheap as anything and can fit Schrader or Presta valves, although switching is a little cumbersome since one has to unscrew the front of the head and reverse the bits inside. The really smart thing about it is the double barrel system, using the thumb lever one can opt to use both barrels to shift a relatively high volume of air, but moving the lever to the second position isolates one barrel so that you can achieve a significantly higher pressure, I typically go to about 80 p.s.i. with no problem, could certainly get to at least 100. The big downside is I bought it in a bike shop in London but have never seen another, I'll be decidedly discombobulated when it finally dies, has anyone ever seen one, I would like to get another in readiness?