I never thought much of having a camera in a phone, I used my Treocam pretty rarely when I did have it. Now I have an E61 without a camera I actually *do* miss it. The rare occasions where I would use it make me think its so convenient to have.

Instant photo evidence when I have had parking tickets and was technically parked legally (happens too often here)... photos of labels to note model numbers... photos of competitors pricing and promotions when I'm out... MMS messaging the odd photo of a product to a customer... its handy once a month or so.