I would never buy a gadget just because it's cute (although if it's really really tiny, I don't know...) and I have zero interest in the Hello Kitty Laptop, but I find myself wanting these San-x cell phone overlays.
As San-x (translated through babelfish) says, "your carrying is changed cutely!" The overlays are translucent, so you can still see your phone's lcd, even if it's tinted in rainbow Afro-Ken. They remove cleanly so you can cycle through all the San-x characters. San-x aims for a slightly older audience than Sanrio's, so I'm pretty sure I won't look at all silly when I take out my Momobuta phone.
San-x doesn't appear to take international orders but if you're lucky enough to live near a

Kinokuniya, their stationery departments carry a huge stock of Sanrio and San-x products. I'm going to start hunting in the Edgewater, NJ location this weekend.