If you continually receive telemarketing calls on your iPhone, Number Guru can help. This handy application is potentially the best free caller ID service available in the App Store, and unlike competitors, Number Guru offers users an unlimited number of lookups, which is great.

As outlined in the app’s release notes, beta features of Number Guru include:

  • Covers about 100% of landlines and 50% of cell phones. Verizon wireless numbers not included.
  • Covers 100% of telemarketers, debt collectors, or 800# numbers. By law they are required to disclose their name or they are spammers!
  • Provides comments from other members to help you identify the type of caller.
  • Free, Unlimited Searches right from your iPhone or iPod Touch.
  • Shows the original carrier. *Note* doesn’t take into account porting numbers to new carriers.
  • Good Karma, Peace, and Serenity

Furthermore, an “alpha” feature allows users to have Number Guru integrate with the Contacts app to “provide better search results.” Because this feature is in its early stages of development, it’s not for everyone – but it is there if you want to try it out.

Users of the application can leave comments on numbers, warning others of spammers, telemarketers or even debt collectors. The details of callers are pulled from public records (much like the developer’s other app, Sex Offender Tracker).

However, most importantly – the app is 100 percent free to use, so check it out and let us know your thoughts on Number Guru in the comments.