Zoomeye Search Engine for Cyberspace

Recently I came across cool search engine for Cyberspace.
This is the place where  you can search by  :

1. Port Numbers
2. Application name and version
3. Location - Country and city
4. Operating System
5. Service name
6. Hostname
7. IP Address
8. CIDR notification - i.e. by IP subnets

This search engine may come in handy while performing external reconnaissance activities.

Searching for IP's with 3389 open port

Here is the User Manual