The present position in the UK is that FL245 is the level that separates Upper and Lower airspace.
Somewhere between November 2006 and March 2007 (I believe the date has not yet been decided) the FL will be reduced to FL195 in line with most of Europe. All European airspace will eventually be the same, with FL195 being the point between Upper and Lower aispace.
Re FL290, this was the level at which vertical separation of 1,000 changed to 2,000 ie 1,000 feet below FL290, 2,000 feet above.
This, of course, has been superceded by RVSM.
Finally, Class B upper airspace has now been replaced by Class C, again this is to bring the UK into line with mainland Europe.