PhoneBoy Speaks Ep 638: ClipSee
The folks from Acoustic Gadgets sent me a ClipSee to review. It's a handfree speakerphone for the iPhone that clips onto your seat belt and you slide your iPhone 4 or 5--with case--into. It makes your iPhone sound louder in the car by directing the sound from the phone up towards your ear. It also makes you, when using your phone to make calls, sound better positioning the iPhone in an optimal position so you can easily be heard.
I like the principle on which this device operates and the fact it works without you having to take your phone out of its case. I like that it's easy to get your phone in and out, yet it remains reasonably secure in the ClipSee. The one downside, which is noted in the provided documentation: you can't charge your phone at the same time.
Other than that, it does exactly what it says on the tin and is excellently priced (about $20 on Amazon).