I have a great K200D but am worried about my Sigme lenses. I know that the body is ok in some weather but my lenses are the weak link. Could anyone help with some good ideas to protect them from light rain or fog :

Thanks guys for all your help. I am flying from Sydney to LA then flying to Las Vagas, staying there for a few days then flying to Calgary. Driving from there to Banff, Lake Louise and Jasper, hopping on board the Rocky Mountianeer Train to Vancouver. Flying to Port Hardy and taking a sea plane to Great Bear Rainforest. Staying there a couple of days then flying back to Port Hardy. Driving around Vancouver Island for a week or so before flying back to Vancouver. Then Back to LA and on to Melbourne before returning home to Adelaide .
So as you can see there is not much driving but thats OK with me as I drive a lot for a living. Fuel prices over here are around $1.60/L so around $6/Gal I think that's right. My work car runs LPG which is much cheaper $0.70/L but not as good economy as regular petrol.
Again thanks for all your tips as they have given me some ideas to buy some more gear

I am new to photography in a way as I have only just purchased a new DSRL camera (PENTAX K200D).I have some equipment ,but am looking to make the most out of my upcoming holiday to Las Vages and Canada B.C. Can I get some ideas as to what I should get in the way of lens filters and cleaning equipment.

Body : Pentax K200D
1st lens : Sigma 17-70mm F2.8-4.5 DC Macro
2nd lens : Sigma 70-300mm F4-5.6 APO DG Macro
2 x 4GB SD cards
Tamrac 3340 carry bag

If I could get some help please.