Wirelessly posted (iPhone: Mozilla/5.0 (iPhone; U; CPU iPhone OS 2_1 like Mac OS X; en-us) AppleWebKit/525.18.1 (KHTML, like Gecko) Version/3.1.1 Mobile/5F136 Safari/525.20)
Some websites if you save them as bookmarks already have preset icons.
However, some don't. What I do for these web pages is I zoom in on something on that webpage that I think would look like a nice icon and then I click on the option to save the page as a bookmark. If I don't like the way the icon looks, I just go back to and reposition the page and attempt to save again.