My husband and I only have newphews. (Actually, I have a niece who was 7 months old at the time of the wedding. But given her age, her family couldn't come). So we had 2 ring bearers, 4 and 6 years old. Each boy walked down the aisle with adult escorts: the 6 year old with his grandparents and the 4 year old with his mother.
I just had them carry a pillow as they were escorted down the aisle and then sit in the front row with adults that they know very well. (Best man held the rings). The 6 year old is ADHD. And the 4 year old gets easily gets moody, and, consequently, unmanageable. I just didn't want to push either of them.
So I went the boring route =P. I like the idea of the ring bearer/s carring a personal object!