Q: Is there a charging stand for the 3G similar to the charger supplied with the original iPhone?
A: Yes, but unlike the original iPhone, the dock is not included with the iPhone 3G. The iPhone 3G Dock (iLounge rating: B+) can be purchased separately for $29.
Apple also sells a three-pack of iPhone 3G Universal Dock adapters for around $10 that will allow you to fit your iPhone 3G properly into the Apple Universal Dock. Note, however, that the iPhone 3G Dock has the unique advantage of including pass-through openings on the bottom for your speakerphone audio, and a line-out port on the back for your iPod audio output (note that your speakerphone audio will not travel through this line-out).
For owners of the Apple Bluetooth Headset, there is unfortunately no dual iPhone and headset charging dock available for the iPhone 3G.