Hard to say
There's always going to be some risk when displaying on the net, especially when you want to show your incredible work in all it's glory at high res. And noone wants to big a big ugly watermark on it, either
Some sites offer the "right click disable" feature which makes it so they can't be saved by right clicking (it will save as a bogus .gif instead), but of course that doesn't stop people from print screening.
I'm sure there will be a suitible compromise somewhere though, I'm just not sure in regards to showing high res stuff. Hey flickr might even have the right click option, so if you could enable that then make sure that they don't have "rights" to your images on their site, then you're in business!
(I use redbubble.com for my photography, but I don't think the display res will be high enough for you)