Certainly painting it comes to mind. Or you could glue shells or rocks all over it. Or you could put -- do they still have that very shallow brick? -- on it. Or you could replace it with a turned post.

I googled it and hit "images" and here is a link to what I got. Mostly it features the mailboxes, but there are some decorated posts shown too.

Here is a link that might be useful: decorated mailbox posts

Thanks. It really is for my daughter but I saw some cute ideas that I will pass on to her.

June