Very good points above:
1. Everyone is different so you have to try different setups
2. Above 55F and you can sweat in your rain gear.

Those Dri Duck jacks are breathable as noted. I found something that’s even more breathable than dri duck and that’s the 02 jackets http://o2rainwear.com/2011/03/original-hooded-jacket/ . They both claim the same material but 02 does something different because I can wear them at 70F and not sweat; not true with dri-ducks.

So I’ve used the following methods:
1. Just get wet.
2. Use trash compactor bag in my back pack. This can take weeks of abuse.
3. Use the 02 jacket. Only 5oz and makes a good pillow.
4. Use wide brim hat (I love this for my glasses)
5. Use $2 poncho (last about 3 days of use if careful) (1.5oz)
6. Use 5oz umbrella (the wind killed this in Wind Rivers last year)
7. Use 8oz umbrella (OK, I’m using the GoLite since it’s tough)

For the last 2 years I’ve been torn between the O2 and cheap poncho. So I actually take the cheap poncho and also cover my backpack with it. And I also bring the Golite umbrella; I’ve stopped many a storms with it. And it’s a great wind shield and shade master. But it’s tricky when I have 2 hiking poles --- that’s another thread in itself.

One more note, in rain, that’s where my footwear shines--- they’re the first thing that dries.

Good luck,
-Barry
-The Rockies and IL bogs were made for Tevas