We took a look at Republic Wireless’ pre-launch buzz a while back, and now invitations to the service are going out to those who signed up for notifications. The WiFi-assisted phone network will charge just $19 a month for unlimited voice, texting and data – with a few caveats. The hybrid connection system requires new hardware, and the first phone being offered is the original LG Optimus at $199 contract-free, though early adopters can get it for just $99.

There’s a catch, naturally. Republic Wireless‘ custom “hybrid” system actively switches between WiFi and mobile voice/data, only using a mobile connection when WiFi isn’t available. The first and so far only mobile operator to partner with Republic is The Now Network, though the company says it’s looking to expand. As long as you stay on WiFi there’s no problem with data overages, but if you use more than 550 minutes of talk, 150 text messages or 300MB of data on the mobile network you may be “encouraged” to end your service.

So, cheap calling with a real cell phone number, plus limited access to calls, texts and data while “roaming” away from an open WiFi hotspot. We’re sure that few people will be intrigued, especially those who gravitate towards cheap pay-as-you-go cell phone plans. But the tech-forward community that Republic seems to be targeting is downright addicted to mobile data, not to mention the latest and greatest in phone hardware. The idea is interesting to be sure, but until Republic signs up some carriers with more breadth and gets some high-end Android hardware, I’ll be begrudgingly stuck with old-school contracts.