When I got a chance to meet with events web site Eventful back in July to look at their iPhone application, the company informed me it was working on some interesting ways to incorporate advertisements. Today, it revealed those plans: It’s the first cross-platform partner of location-based ad-targeting service 1020 Placecast.

What this means is that Placecast will be in charge of serving up advertisements on Eventful’s webpages and on its mobile site — including the application built for the iPhone. The mobile element is important because Placecast will have access to the device’s GPS chips to serve up ads based on where a user is. Because of this, these ads will demand higher CPMs (cost per mille, or the cost per a thousand impressions) and should be more relevant to the user, the company says.

Since Eventful is all about local events, it makes sense that it would team up with an advertising partner that targeted local areas. This will work on the service’s website as well by utilizing elements such as zip codes and other page content.

The San Francisco, Calif.-based Placecast was founded in 2005. It received funding from Voyager Capital and Onset Ventures.