Good call! I was thinking that something like that could do it. (My default thought for that type of thing is a Greasemonkey script, which iPhone Safari doesn't support.)
Btw, an easier way is just to paste the code into the address bar.
The reason I mention a bookmark is to have it handy anytime you want to save a page to the homescreen, and because you can then create it from your Mac/PC and it can sync. Easier than typing it on an iPhone.
Btw, an easier way is just to paste the code into the address bar.