By "basic" I mean anyone who knows how to use the 
paint and eyedropper tools. I can think of at least 
half a dozen ways you can do this. Heck, there's 
even a way the program will do it automatically. 
Still, I'm agreeing with you. Like I said before, 
watermarking is probably enough to avert some 
theft. It's a good idea if you're concerned about 
this kind of thing. There's not much else you can 
do short of blacking out half your image or adding 
a gradient filter. Still, what's the point of 
displaying your artwork if you have to muck it up 
to keep it "safe"? I suppose you just have to 
understand the risks, chose whether or not to 
display, and do what you can to keep theives at 
bay. 

That's at ^_^!

toad