I don't know if the stock Android launcher has this feature, but I use ADW Launcher which has the option of locking the icons. I like it phenomenally more over the default launcher. There's just a lot more options for customization like locking the icons, changing the # of col/rows for icons, app drawer behavior, gestures, themes, doc, etc.

There's a free and paid version. I finally bought it, but used the free for years. Honestly don't really know the difference.