Re: New, simple online wallet: www.instawallet.org - no signup required
It seems you are correct, that referrer is transferred when linking to another SSL site. I will have to think about this, but as I don't have outgoing SSL links, it should be fine at the moment. Redirecting in the way you describe would be an option, but I'm not sure I like it much. I consider seeing your actual wallet link in the address bar a usability feature.
I agree that having the wallet link in your address bar is a usability feature (though it could also be done with hash fragments). Perhaps a better approach is to make sure that all outgoing links go through a redirector?
E.g. http://redirect.instawallet.org/?url=http://google.com/ -> http://google.com
This will make sure all the referrer information is cleansed before leaving the site.
Also great job.
I worry what your wallet data looks like after I tried a bunch of random urls and they all worked. Sorry about that. 
- shazow