The right side of the Samsung Focus has a volume rocker and a camera button.
Overall, the Focus is quite a slim device, so you should have no problem slipping this into a pants pocket. We did think it felt a bit more plasticky than the other devices, however.
The Samsung Omnia 7 is a Windows Phone 7 device for the international market, though pricing and carrier information were not released at this time. The main difference between the Omnia 7 and the Focus is in hardware. For example, the Omnia 7 features a physical Menu button whereas the Focus has all touch-sensitive keys.