Thanks Pete!
I use a Manfrotto 055Pro tripod, which is very robust, very easy to adjust and can get right down to the ground (using the removable centre column). It can also reach as high as eye level (for me, at 6' 2", thats quite good!). However, my big nit with it is the weight!! At 2.4Kg [just over 5lbs in old money

], you can certainly feel it after a day!!
I use a Manfrotto 322RC2 head, which is simply fantastic! I urge you to try one. Basically, it is a quick release ball head. You squeeze the trigger, position the shot and let go of the trigger. No twisting or tightening knobs. No adjusting x-axis, then y-axis. Just one easy movement, and it's unbelievably strong!! There is no travel* in the head whatsoever with my 300D and 150mm lens.
*technical term (get me!) which means that where you point it is where it stays, it doesn't move under the weight of the lens after framing.
Finally, you can buy a low angle adaptor (Manfrotto 055LAA) for £12 which make the whole process easier when you're near the ground.
I don't know whether any other manufacturers offer anything similar to the 322RC2 head, which is why I went Manfrotto. It is such a good piece of kit for working in the field, I will always use a head like this and therefore will always buy Manfrotto.
Cheers, Chris
[PS: If anybody from Manfrotto reads this, please can you take note of my great review and send me a Carbon Fibre tripod as reward!]
[PPS: I wonder whether the next generation Macro lenses from Canon will come with Image Stabilisation? Wouldn't that be good!]