Hi Nick,
Ah, ok, it's the I've got a hammer now everything looks like a nail kind of thing ;-)

Well, as with most things there are more than one way to skin a cat. What I'd do is probably something like this (for 12F683 but not tested):
Code:
' CMCON, ANSEL, TRIS, whatever not shown here!

oldCount VAR BYTE
LED VAR GPIO.0

oldCount = 0    'Clear count
LED = 0    ' Turn off LED

' Set TMR0 up as a counter, signal fed into T0CKI pin
OPTION_REG.5 = 1

Main:
   If TMR0 <> oldCnt THEN    ' There has been pulses since last time we checked
       LED = 1
   ELSE
       LED = 0
   ENDIF

   oldCnt = TMR0      ' Store current count

' Now wait a bit to allow any new pulses to "tickle" the counter.
' Shortest PauseUs time @8Mhz is 12us.
' If faster response is needed replace with a copule of @NOP (each taking 500ns @8MHz) or try without any delay at all. 

   PauseUs 25  ' Or go do something else usefull instead....

Goto Main

Anyway, that's one idea....

/Henrik.