The hybrid Treo is available from the company's web site for $399 (£279) if bought in conjunction with a GSM from US providers Cingular Wireless or VoiceStream Wireless.
Users can also purchase the Treo online without the Cingular or VoiceStream service for $549 (£405). The company has pledged to deliver within three weeks. Orders placed with VoiceStream service plans are expected to begin shipping on 25 February.
The GSM phone/PDA runs the Palm OS and uses a small keyboard for data entry. The Treo is powered by Motorola's DragonBall VZ processor and comes with 16Mbytes of memory. The battery allows for up to 2.5 hours of talk time, or 60 hours of standby while the phone unit is switched on, Handspring said.
Handspring's plans for reaching profitability by the middle of the year are dependent on Treo sales, Donna Dubinsky, president and chief executive officer at Handspring conceded in January. The company expects revenue to reach $86m (£60m) to $96m (£67m) by the company's fourth quarter, ending in June.
In January Hong Kong was the first country in the world to have Treo available on the shelves, at HK$4,380 (£393). The Treo was also made available in Singapore.
Plans to launch the Treo in Europe were outlined in January. MMO2 - formerly BT's mobile communications arm - will distribute the device for use on its GSM networks in Germany, Ireland, the Netherlands and the UK beginning in the second quarter.
Handspring also dropped the price of its Visor Edge handheld to $199 (£139).