Personal Digital Assistants (PDAs) came into being once the digital technology advancements started supplying their utilities for the business community. Over years office automation has come up from their typewriter age to calculators, electronic organizers, computers, and cell phones.  Business users wanted a connecting source with their office whenever they were away from it, to get access to latest info as to what is happening there.
This necessitated synchronization of a hand-held and mobile device which has functions of a mini computer in it and also able to synchronize remotely with the parent computer in office. At the time of inception PDAs were introduced as paper-less day planner, just to organize the to-do lists for the day, information on contacts, addresses, phone numbers, keeping track of one’s calendar information etc.
PDAs performed the tasks of a pocket computer, as people used the first generation computers without Internet access. Then game all the upgraded technologies in PDA designs one by one to make them more useful with multiple functions and applications.  Today the PDA manufacturing technology is trotting in gallops and you get announcement of a new function every other day from the PDA models and designs.
The PDAs available in the market are evaluated on their benchmark performances and out of the present generation PDAs here are the few for consideration:
Palm Z22: A basic PDA device with no wireless capabilities. This can be used as paper day planner, with a color screen of 160 x 160 pixels and 32 MB of space for storing your data.
Palm Tungsten E2: A budget performance PDA, without Wi-Fi, but an excellent organizer for official work, with 32 MB memory and capability for increasing the storage space with SD slot provided.  Battery life is long and it can play MP3s, photos, videos etc. in 320 x 320 pixels.
Palm TX : Recommended as Best PDA. It has multi-media functions with Wi-Fi and access to wireless hotspots. With Palm Blazer web browser; Dataviz Documents To Go software; 3.7 inch screen ; 320 x 480 pixels; comes with 128MB non-volatile memory but can be increased by adding Secure Digital Card; compatible with Windows and Mac operating systems.