I had exactly this question a couple of years ago when I thought of using my old Pentax K mount lenses on a DSLR. Yes they are compatible (well Pentax lenses are) in the sense that they fit the DSLR camera body but there are a multitude of other considerations due to technological changes.
For me, sensor size in the DSLR was the main issue, which effectively meant my favourite 20mm lens (SLR film format) would give an angle of coverage equivalent to approx 30 - 36mm in old money when attached to a modernish DSLR
That was the killer. Old lenses can fit but they don't perform to the way they were designed. Photo quality is fine, better some say, but you lose coverage and other DSLR features.
Sorry to say I've bitten the bullet and converted to DSLR kit plus a compact digital camera for 100% of my photography now. My 35mm stuff is either on a shelf, cos it looks pretty and feels right, or destined for ebay collectors
Another vote for the Nikon D50 and also the Pentax K2000 here.
Use a Lumix TZ18 compact as its the size of a fag packet and great features, but I just couldn't live withouts some type of slr capability. Looking at a LCD screen in daylight without any veiwfinder is a PITA
£200 should get you a decent s/h Nikon or Pentax kit with two lenses giving a 35mm equivalent of 24mm - 400mm or thereabouts, plus a few accessories
WANTED: Kona Sex One rear brake canti hanger pivot thingy - GOT ONE!
I could be tempted by a 19" - 21" Dave Yates (mountain) frame.................and no I still don't do trail centreshttp://www.corrieyairack.org/index2.html