In reply to charltonss: Personally I would skip waterproof trousers and just get some gaiters. If you have a good sized jacket, it will cover down to below crotch height and if you wear some quick drying trousers, they will dry out with your body heat when you are walking in maybe only 30 minutes or less after a really heavy shower. I very, very rarely wear waterproof trousers, they really only seem necessary when it is pissing rain constantly all day (in which case there doesn't seem to be a lot of point in going out in the first place) and when you are wearing waterproof trousers, walking becomes so much more of an effort because they are always restrictive of leg movement.
If you do a lot of hiking, you could do a lot worse than get a big properly engineered umbrella too. It cuts down the wind and works as well or better than a waterproof jacket (in all but the windiest conditions). I also find that after a prolonged walk in fairly windy conditions with intermittant rain, I have been hunching my shoulders and my face has been hammered by the weather so I'm pretty knackered, I feel a lot better when using an umbrella because I stand up straighter and my head is basically completely protected from the weather. If it is warmish and you are sweating, an umbrella gives the ultimate breathability that no waterproof will ever approach.
Only disadvantages of an umbrella are that it's more weight to carry, it can't be used in severe wind, it can make walking into the wind more difficult and if you are angling in low against the wind, it can cut down your visibility of terrain in front/side of you.