recommend me a bag/rucksack

[tattymarbots]

looking for a bag/rucksack which will hold 2 nikon dslr's with lenses attached
one is an 18-105, other is a 70-300.

seen somewhere rucksacks with separate compartment for snacks/clothes and a laptop part.
must be waterproof or have waterproof cover

[CarMac]

How much you got to spend?

[Don]

Lowepro DryZone Rover - rucksack with waterproof camera case. Might not hold two DSLRs, though.
Lowepro DryZone 100 - waterproof backpack
Lowepro DryZone 200 - huge waterproof backpack

They also do non waterproof jobbies that have an "all-weather" pull out cover. "AW".

Personally I have a Lowepro Rover. It isn't all-weather or waterproof but cost a great deal less and I paid £2.99 for a waterproof rucksack cover...

http://www.lowepro.com

[itsnotarace]

I have one of these - http://www.cambags.com/bag-type/backpacks/crumpler... which meets all your requirements

Don't think they are sold any more but they do similar ones (Big Cheese/Italian Connection)

[clonmult]

I've got a Lowepro Slingshot (A100?). Its not bad at all, but I barely use it .... in fact, the camera hasn't been in it for about 4 months. Its got a waterproof cover that comes out of the base and wraps around the whole thing.

[Mr E Driver]

I have a Kata and they have an extensive range to suit most requirements.