It works, but can be touch and go when used with Touch Tone equipment at
the other end. I can use it to call into some of my customers'
voicemail, but not my own and its the same VM unit. Can't fax with it.

Yeah, I bought one to play with.  I have an extended work/vacation trip
coming up this summer, so I bought one to forward my home phone to while
away (normally one could just forward to a cellphone, but my cellphone is a
business phone with a different long distance area code, so my forwards
would cost me LD fees!) I'll give it to my son as a "teen line" when I'm
done with it.

It works as advertised- it's just a simple USB-to-RJ11 converter with a
small USB flash drive (to hold their installation software.)  Sound quality
is fine as VoIP goes, but because it's (eventually going to be) an ad-
supported service (the softphone software has a big banner space on the
left that currently displays MagicJack tips and info) they don't let you
use SIP hardware/adapters with the service (even though it's a generic SIP-
compliant service) so you need to run it on a PC 24/7 like Skype.

In addition, the software won't run without the Magicjack plugged in (even
if you just want to use a headset) probably to give the illusion that the
"magic" is in the jack, rather than in the rebranded SJLabs SJPhone software.

(MagicJack, and SJ are both owned by YMax, a small CLEC.)  While software
lets you switch between using the MJ device or a headset, it won't let you
use any other sound hardware, like my current USB VoIP handsets.  (Ideally
I wanted to schlep less stuff on trip- I wanted one USB handset for Skype,
Voicestick and MJ, now I need my USB phone, the MJ and a cheap phone (or
use a hotel phone plugged into the MJ, or just use a headset for
everything, I guess.)

Even with ads I don't think a $20/year phone service is sustainable
financially, so I think they'll disappear when the VC money runs out.  For
$40 it's a cheap toy, and a darn cheap way to have a spare "throwaway"
line.  Because of the needs-a-running-PC requirement, I wouldn't use it as
a landline replacement unless they eventually let people use standalone
telephone adapter hardware (which they won't, because then you wouldn't see
the adverts!)

BTW, unlike DTC, I've had no problems with touch tones so far (but that's
always touchy with VoIP) and my one test fax worked fine.  (But to be fair,
faxing over VoIP is also a very YMMV thing.  I've only sent one fax through
MJ on one attempt.  Even a .250 hitter can bat 1.000 with only one at-bat!)
;-)