Been A PDA user for years and am still packing my 4 yrs old Sony CLIE NZ90 which has one of the best colour and large screen viewer for a PDA. Although I use the proprietary magixstick memory module to store my pictures and other data (plus use it with my Sony S70 digital camera) it has a CF slot which Sony claims can't be use with any CF devices apart from their wireless "CF type I&II slot" transmitter. But some smart geek managed to coax the PDA to accept a CF memory module by using a hack software install into the PDA. With patch,I could now view my large capacity 1gig CF card of mp3,avi,jpeg,gif..etc. But not RAW. I believe there are PDA picture viewer s/w that allow RAW (though I doubt it..can't find one that opens Nikon RAW) but I can't see how using it is productive even if you found one. The D70 Large Fine Jpeg pictures are already a challenge for the PDA left along a RAW digital photo file.
Personally, it is too slow to be useful or practical when you are in the midst of shooting. Use it to check your shots? As in taking the memory card out of your camera, slot it into your PDA, enlarge it to see if you shot the picture sharp enough or requires a reshoot? If you shot like 50 scenes you can't be taking it out 50 times to check and reshoot. If you want to check for colour correction, your PDA is not a calibrated monitor to do so. Sure you can enlarge it to 100% picture size to see if it is sharp but have you guys tried it even with a large fine jpeg file? A 8 megapixel file when opened is about 18mb. You also need a very powerful graphic engine and lots of built-in ram memory in order to process the file fast enough to view. I have used a few graphic s/w in my PDA to view picture files including the viewer Sony provided. But all still takes like forever to open them in multi thumb size size mode. It need to take a look at the picture data then convert it to thumbsize for each one. My PDA/S/W would load up all of them when I open the viewer and it takes a long time to load the entire pictures collection of say, a 1 gig card. I could click one of them while it was still loading, it would still take a while for it to draw the large jpeg file on my screen and when I go back to the picture list , it try to reload the entire collection again...thumbnail picture by thumbnail picture.
As you run out of ram, it will try to use your CF or magixstick to buffer all the thumbsizes. Also the built-in ram type is not exactly the fastest type in the market too. For normal viewing when I am not shooting, I guess I could wait abit but it is so slow that I rather be viewing them on my PC or Notebook or if I am just itchy to view (or showoff) on the MRT or some coffee bar, a more dedicated portable viewer like maybe the new Epson Player or the Creative Zen ( or was that Yen?) that have large viewing screens would be better. I still do use my CLIE to view my pictures but only what I have edited and decided to keep in my PDA memory or memory module as keepsakes. That's my personal view lah as a PDA user
I am not sure what Octane69 meant by "T3 screen can be extended to be about the same size of a 4R photo" but I am sure there is no T3 screen I know that is the size of a 4R print. That has to be a pretty large LCD screen if so. But if he meant that he can zoom in to see what fine detail it has at 100% zoom view size ..then yes the T3 can do that but then again any PDA can do that too.
Small and easy to carry? Yes I guess it is but easy to use? I don't think so. Too many troublesome stuff to content myself with to be useful when using it on the go...especially if I am shooting. And since the PDA does not have a HDD, it is of no use to me for quick standby storage as well. So it is only good enough for viewing purposes abeit it is slow to access and slow to render lots of large digital photo shoots.
So if you are buying a PDA and your primary use is as a viewer for your photographic shoot, I would strongly urge you to reconsider. Also if you have not already notice PDA is on the wane and fading fast...there are lesser and lesser 3rd party development for it as the mobile phone with its convergence of incorporating PDA-like functionality into it phone are muscling out the PDA industry. Frankly I wish it did not as I hate convergence of technology. I prefer a PDA is just a PDA and a phone..just a damn phone. heheh but that's another story.