Here are some fast observations:
Set up was fast, easy. A confirmation email and I was off and running.
To get a 3Jam number you have to pay as little as $4.99 per month. GoogleVoice is free.
Like GoogleVoice you have to buy outbound minutes. You also have to pay for SMS traffic, while at GoogleVoice SMS origination via the web interface is free.
Calls to Skype are permitted. Right now you can't directly call Skype with GoogleVoice unless you have a SkypeIn number or Gizmo5 that can point your calls to Skype for GoogleVoice customers due to the peering relationship between GV and Gizmo that I helped establish a few years ago, and ironically, 3Jam is using OpenSky to ring calls inbound to my Skype ID.
The voice on the answering engine is mechanical. It sounds like something out of StarWars. I'll eventually get around to changing it.
3Jam is not a new company, debuting at DEMO in 2006 and has spent time working with messaging applications, mostly built around SMS. One app they have made available is a Twitter app that is useful to those outside the USA who need to be twetted and to tweet. A Windows only desktop SMS app is in place already, as is a Blackberry Threaded SMS application.
My take-right now the 3Jam service looks to be really strong in the SMS space and has decided to leverage that and jump into the find me/follow me game, offer Local Number Portability and bundle in some other services, ala Google Voice.
Clearly right now they are falling into the "Me Too, Me Also" space and are looking to become a "Me Different" company in the unified space, just as they achieved in the SMS/Texting space with the group texting solution they delivered to socially networked carriers, but unfortunately without more to the new service, it hasn't gotten there, yet. Now if they blended the features of former client TalkPlus' capabilities to the service (Note I remain an option holder in TalkPlus for transparency purposes) they would be different, and would have something that could outflank GoogleVoice.
These folks aren't slouches. They have some serious money behind them in NEA and Norwest Venture Partners, have a nice customer list who they provide white label services using the 3jam platform to including Peek, Samsung, Motorola and Virgin Mobile USA (or until the Sprint merger closes and they learn what happens next.)
As an option to GoogleVoice, 3Jam is clearly getting it's groove on...time will tell just how well they play in a space which is only going to get more crowded as the mobile operators begin to offer more new features that previously required third parties to provide them.