I have used Windex and kleenex to clean my laptop screen. It does a good job with no streaks or marks on the screen. I didn't squirt windex on the screen though - just apply a small amount to the kleenex and then wipe.
As for the keyboard you could probably do the same thing. Also, a can of compressed air is good for blowing out the dust and crumbs that get under the keys.
You can get a $10 pack of already prepared wips and try it out. It is a two step process of wiping with the damp cloth, and "polishing" with the dry cloth provided in the packs.
It really does work well and keeps static from building up (hence dust, etc...).
You can use it on regular computer screens, DVDs, CDs, LCD displays, optical mice, etc......