I managed to visit Morris Photo in Chipping Norton this afternoon. It was all a bit impromptu but I'm glad I did it. They have a really good selection of 'pods and it quickly became evident that 30mins playing with a few beats many hours of web research.
To the OP who wanted a tripod for £50, I was extremely impressed with a Velbon Ultra Luxi F for £54. Very light & compact, quite tall without extending the centre column and it seemed very sturdy. The guy in the shop seemed knowledgeable and helpful and suggested that it would be OK with a DSLR and small to moderate telephoto lens. If price and weight are important this seemed like a very good choice indeed. I may yet come back and buy one of these purely for travel use.
I bought a Manfrotto 190XProB with a 486RC2 ballhead / QR plate. I reckon it's about as heavy as I'd tolerate and still use. The ballhead vs 3-way seems to be a personal choice thing but I felt that ease, speed and less bulk were more important to me than the precision (I can always tidy up with crop & straighten in PS if need be.)The combo cost me £129 which is their ebay shop price. The regular price is a bit more but I asked for this and it was readily given (perhaps I should have haggled more

).
Some may be happier with 055s - they're taller but getting a bit heavy for my liking. I worried that if I bought this it would live in my car boot but never come out.
To Gordon: The centre column on the 190XPro can be switched (very easily) to horizontal but not at all angles between horizontal & vertical. They had a Benbo that does that sort of thing.
Time will tell whether this 'pod is as good as I hope. One thing that was very clear to me from todays exercise is that there are a lot of trade-offs in choosing a tripod Price, weight, size, ease of use, precision etc etc) and it's easier to evaluate that trade-off in the flesh. Maybe the ideal answer is having more than one???