Nick have you ever bought a new camera yet?
For low light without flash a DSLR will outperform any compact by a big margin.
The disadvantage: size and prize of decent optics.
The Nikon D40 is good but inexpensive though.
If a compact there is one which outshines all others in low light / high ISO performance, even almost rivals DSLRs: the Fuji F31fd ( also the earlier F30, F10 and F11 )
And so does the bigger Fuji S6000fd ( S6500fd ) which uses the same, very sensitive sensor which goes up to ISO 3200 those cameras have become famous for, but in a bigger body with a bigger zoom range. ( note that the later F40, F50, also the S5700 mentioned be spreetaper and S8000fd also are also good low light cameras, but just not as good )
for general info on cameras I recommend:
http://www.dpreview.com/ ( little bit Canon biased though, but any DSLR will be good, Canon, Nikon, Pentax, Olympus... )
To compare image quality, specially of high ISO:
http://www.imaging-resource.com/IMCOMP/COMPS01.HTMto get to the Fuji you must select 'all cameras' and choose the Fuji F30 ( F31 is roughly the same + some small improvements )
or also check my fotos at:
http://flickr.com/photos/8003463@N03/ Most of the photos there had been taken with my Fuji F31fd, some also with my Minolta A2 and Ricoh R3. Why most with the F31? The image quality of the A2 is superior, but the F31 fits in my pocket and I can shoot without the use of the flash, if wanted unnoticed, at pretty much any light situation.
cheers,
kuuan