Nerida,
That's what I keep telling myself. They all think I'm crazy now, but in 10 years, I'll be much better off. My mother habitually tanned when she was younger, and she constantly reminds me to reapply sunscreen. In the photos, I'm actually a bit sunburned! I went on vacation, and despite my best efforts, I've got a little bit of sun.
I think I'll go for the 26" I'm pretty tall too (5'6") and I think the 16" might look a bit silly. I really only considered it because I thought it was a good "standard" piece to get (and I always stare at my friend's strand whenever she wears it).