iControlPad updated their site with renderings of the planned iControlPad as well as answers to some frequent questions. iControlPad is a hardware accessory that will give the iPhone and iPod Touch PSP-style buttons for playing games.
The developers report that the iControlPad will be priced at (probably) under $30 and be shipping in July. They plan on supporting the iPhone and iPod Touch. At present, the iControlPad requires a jailbroken iPhone.