Living in a high humidity environment and being a knife freak I'm a bit of an oil and rust preventative nut myself.
For cleaning a blade after use, I favour WD-40. I also use Birchwood-Casey Sheath (gun product) and Break-Free.
If you're using the knife for food prep, I got some stuff called Neo-Ballistol from a gun shop a while back. It's a German product, which is pretty fascinating, as it was apparently used in WWII by the Wehrmacht to clean their equipment and (get this) as a preservative for rubber, leather, and even to keep their animal's fur coats in good shape (!). The stuff is also sold in gel tablet form, and apparently will keep your guts in good working order. I'd like to know if anyone else has used this product. So far it seems to work pretty well.
For long term storage, I use Marine Tuf-Cloth. It does leave quite a bit of residue though.
I've just ordered my first forged custom in O-1 tool steel, so I'm going to be keeping a close eye on that one. Most of my knives are stainless or coated. For my Cold Steel mini-kukri, which is carbon steel, I use an automotive ball-bearing grease along the edge.
Never thought of vaseline.... learn something new every day! :thumbup: