• Operating system
• Microsoft
• Palm
• Symbian
• RIM
• Tech specs
• Memory
• Form factors
• Screen
• Size
• Touchscreen vs Keypad
• Battery
• Connectivity
• Bluetooth
• WiFi
• GSM/GPRS
• GPS
• Multimedia

Connectivity

USB connectivity is standard across PDAs and provides fast, efficient data transfer and recharging. Dock connectors are less common for synchronisation, but are included with some models. Any of the Microsoft Windows OS devices will easily synchronise with Outlook for email, contacts, memos and to do lists. Palm OS devices will support Outlook for synchronisation, as well as its own Palm Desktop application.

Synchronisation is also used to transfer files, such as multimedia files, applications and other data, between PDA and desktop computer. PDAs with infra-red connectivity can transfer data between a PDA and desktop PC or another device by beaming data such as virtual business cards and contact details at a speed of 115.2Kbps.

Bluetooth

Bluetooth is a wireless technology for data transmission at up to 3Mbps, which is also used in smartphones and 3G phones. It has spawned a plethora of devices and applications, such as headphones and headsets, printer connectivity, virtual dating and even certain viruses. High-end PDAs include Bluetooth, but some devices can add connectivity with a Bluetooth adaptor card that goes into one of the storage card slots.

WiFi

A PDA with WiFi connectivity can connect to the internet through the 802.11b/g specification which provides for transmission of data over the 2.5GHz band. PDAs with WiFi can connect to the internet for web browsing and emailing in hot spots or wireless internet zones both in Australia and overseas. WiFi connectivity can also be added to some PDAs through an add-on card if it isn't built in.

GSM/GPRS

Some PDAs now have GSM/GPRS connectivity for voice and/or data connectivity. A model with a slot for a SIM card can be used as a phone, while others can be used for data transfer through GPRS which provides for internet and POP3/IMAP email at speeds of about 56Kbps. It's also possible to use an adaptor card to provide GSM/GPRS functionality in PDAs that don't have this built in.

GPS

There are a small number of PDAs on the market that are also GPS devices and can be used for mobile connectivity and satellite-based navigation. They tend to be in the mid-range of devices, but still have good processing speed and storage space. In addition, a PDA with Bluetooth can use a Bluetooth GPS receiver for real-time mapping via GPS.