Two terrain texture questions

Do terrain textures need to tile? A friend just bought a couple of items, and I am trying to help him get some unusual textures. Does SL do some kind of on the fly tiling?

A related question, is there an easy way to make a texture, such as sand, into a tiled one. What I have tried is cutting it in fourths, rearraning it, and then trying to blur/blend the boundary. Is there a better way?

#2
if you happen to use the gimp there is this
http://www.manucornet.net/Informatique/Texturize.php

im shure theres something simmilar for photoshop

Above, Osgeld Barmy suggested a plugin called Texturize. I am here to say

AWSOME!

This cool device will take a small texture, say 128x128, and convert it into a larger seamless tile texture, say 512x512. it does not just repeat the original. Instead, it appears to use some sophisticated matching to replicate it while smoothing and varying it. The site includes a reference to an academic paper which describes the algorithm.

Verycool.

As for Gimp, I had avoided going that way until now. I had to download and confugure Gimp to try this plugin. For those of you, like me, who have been hesitant, let me say that the Gimp installation was very painless, and that Gimp looks to me to be quite powerful.

iIn particular, it does channels and transparencies in a very plain and obvious way.