The Belkin
TuneBase
is a FM transmitter for use with the iPhone and iPod. Audio from the
iDevice will be sent via low-power FM radio to the car’s stereo.

(The image on Flickr has notes, click on it to see them!)
I used to have a FM-transmitter that attached directly to an iPod,
which was compact but the connection was fiddly. In addition, the
device worked poorly with the iPhone. There was a lot of interference
from the iPhone’s mobile interface.
There are some very good things about this gadget, and a few drawbacks.
When I got it, I was worried that the “pillar” part would interfere
with my stick shift. But it’s not a big problem. Once in a while I
happen to hit the controls circled around the frequency display but
there’s no problem shifting gears.
You should have a look at the placement of the cig lighter in your car
before getting one though. It’s optimal if the ligher socket is part
of a vertical surface. The frequency display is a bit hard for me to
see from the driver’s position; on the other hand, it’s not something
that changes a lot.
There’s an option to let the unit scan for a free channel to transmit
on. I haven’t used this option, as I found a channel that works for me
a long time ago. But when driving long distances this should prove
useful.
The part holding the iPhone is rotatable so you can have vertical or
horisontal orientation. It’s relatively easy to change playlists
etc. using it. It’s much more preferable to having the iPhone lying
loose between the seats.
To connect it fully, you need to connect a lead to the headphone jack
but this is quickly done. I have a silicone sleeve on my iPhone, it’s
a bit tight but not problem to connect.
You control playback and calls with a button below the iPhone, it’s a
bit fiddly to double-click to skip tracks.
Sound quality is decent for an FM transmitter. There’s a standard
3.5mm stereo output built into the pillar. You can use that to connect
to the stereo if you have that input jack. There’s also a USB socket
for more charging options.
Calls work OK if you’re already tuned in to the channel the device
is broadcasting on. If not, you’ll have to switch to it, and it takes
a few seconds for the Tunebase to be “picked up” by the stereo. If
you’re making a lot of calls, and regularly listen to FM radio, this
may not be optimal.
The few calls I’ve made have been rather hard to hear, according to my
interlocutors.
I’m very happy with the TuneBase, it’s a great way to listen to audio
from the iPhone while driving!