This JBL speaker dock is compatible with most iPhone and iPod models, but be sure to check with the product pages in regards to your own model before purchasing.
For example, I tested the Micro III speaker set out with my iPhone 4. There is an included plastic adapter with two rubberized, attachable surfaces to adjust for the iPhone 4 and the most recent iPod touch. However, while they might fit, the On Stage Micro III won't charge your iOS device.
If you have another MP3 player or audio device you'd like to use with these speakers, there is a USB port and audio jack around the back.
Then you need power. You have either the option of using the included DC power adapter and plugging that into the wall, or pick up a 4-pack of AA batteries because they're not included. Once ready, hit the power button near the connectivity ports on the back and wait for the center to light up.
Everything is controlled by the included remote control. It's ultra-light (be careful not to lose it), and works well. Basically, it just adjusts the audio settings, scrolls through your iTunes list, plays and pauses, etc. However, I recommend just setting your iPod to random or making a playlist since it gets annoying having to fiddle with the control ever song.
Audio quality was fairly good for the most part, only being a bit scratch when on the maximum setting. Unfortunately, you can't view bars or a range on your iPhone. It's only controlled by the remote control, and you can guess with your own ears.
This is probably perfect for your bedroom, office, or even small to medium-sized gatherings at home or maybe a picnic in the park.
Overall, the JBL On Stage Micro III is a very straightforward device. Essentially, plug in your iPod/iPhone, figure out your power source and you're golden.
The JBL On Stage Micro III is available now for $119.95. If you have a 4-pack of AA batteries (cheaper to go rechargeable in the long run), then this speaker dock is very portable and quite useful in that sense.
But as an iPod/iPhone speaker dock, it's only got one use: music playback. There are many, many speaker docks on the market that aren't much larger than this one and offer more features (at least an alarm clock!) for $30-$50 less.