what POIs (Point of Interests) DB can I use for a commercial app

I need a POI database for a startup project I am working on - it will be a free basic version and a premium paid for version in the sense that user will pay a monthly subscription.

I would like to use foursquare type checkin to places and plancast type functionality to search for places (one-line search).开发者_开发百科 Ie I need to:

• perform a search for POIs around a location
• associate users to that POI, with a time stamp
• allow users to add own POIs
• provide free-text search for POIs (a la google one-line search)

Google API allows great search, but I understand there are limits in number of requests that can be done? This would prevent scaling, and may result in application breaking when too many users. Also what does google T&C say about using this in a paid for service?

Openstreetmap I understand does not have these contstraints, but do they also provide a good one-line search type API? Or how could I solve this?

have a look at http://eventful.com/ or http://qype.com - they both have APIs you can call to get find out whats happening near you. You can convert these events into POIs in your application. The APIs are free to use (your app just need to credit Eventful or Qype).

Take a look at the API at http://compass.webservius.com - may not have everything you need, but has very rich data on 16+ million business locations in the USA.