An iPhone and iPod Touch Remote Control application has been requested several times on the Boxee Forums and based on a twitter post by a boxee rep, it looks like boxee is actually working on their own iPhone/iPod Touch app that does just that.
Boxee, a popular HTPC project based on XBMC is reportedly testing the iPhone remote app internally and are waiting for Apple to approve the app for the iPhone app store. According to the “tweets” the first version of the Boxee/iPhone app will be a simple remote – so probably will not include playback functions within the iPhone at first.
If you can’t wait for the official app, there already is an iPhone web interface you can use with boxee. Just be sure your web interface server option is turned on, under settings -> network –> servers. Then point your iPhone (or iPod Touch) to http://appletv.local:8888/iphone/. It’s a simple web-based interface and is fairly limited – similar to the offering for XBMC (can’t access any of the native Boxee content such as social feeds, integrated content such as hulu, revision 3, or rss feeds, ect.), but it does list the content and provides play controls to launch the media in Boxee.