The only thing you'll be doing by buying the PC133 RAM would be future proofing it very slightly. Not really worth it, if its cheaper to get PC100 then get that.
actually the pc133 is cheaper. The Other One these things suck I'm upgrading the ram on it for a guy up at work they are ultra small but only have 500 mhz celeron can only hold up to 256 mb ram have no upgrade options really. He is only going to be using it for word processing and some web surfing and email.
Yeah thats what I told him but he wanted me to make it a bit faster so i'm taking the *shudders* 64 megs of RAM its got in it out and puttin 2 128 sticks in.