This is fantastic. I've been wanting something like this for awhile now.

But, yeah, I would definitely consider trashing the IPs. I wouldn't keep IPs in a log either. A service like this shouldn't even need logins or passwords (since the data is all available in blockexplorer anyway). I'd just let someone enter a bunch of addresses and then give them a unique URL to access them at. Since it's read-only, it's ultimately sort of like a URL shortener.

Sweet! Take care.