As a very diligent blogger or webmaster, you may need to search public WHOIS databases for your work. Take a look at Deep Whois, maybe the utility app can meet your requirements.
Deep Whois is a very practical utility app developed by Pavel Ahafonau, and designed to offer you an easy way to check public WHOIS databases including hostnames, domains, IDNs, IP addresses, IP networks and autonomous systems (ASNs). The iPhone app features minimalistic user interface, all you need to do is just to type the domain or IP address that you need to search in the bar, tapping “Search”, after a while, all the info about the domain or IP address will be shown on your iPhone or iPod touch. The result can be pasted or sent via Email. The result history allows you to check the former searching results.
Deep Whois with a size of 3.3 MB is compatible with iPhone, iPod touch and iPad running iOS 4.0 or later. The iPhone app is free for a limited time at present. If you’re interested, jump to App Store for more details.