a 20/100 watt energy saving bulb in a lamp with a white diffuser ( old sheet ) would do or even 2 to minimize shadows
it would have to be reasonably close hence the energy saver type bulb so it won't melt your face off
thats the cheap method...
or you could get something along these lines
http://www.stevesphotoshop.co.uk/day...bulb_T75P.html
good luck...