I'm using the iPod Touch 3G in addition to the Sprint Samsung Moment for a variety of reasons. (The picture shows a side-by-side comparison with the Touch on the left.)
The Touch has more screen area, plus I can use it on a Wi-Fi network, saving the batteries on my phone. Safari provides a decent browsing experience, not only for the regular Web sites but also for the mobile sites, which are growing in number. The Apple App Store gives me more options than Android Market. My favorite apps include Instapaper, Stanza (ebook reader) and GeeTasks (sync's with Google Tasks and Android gTasks).
This morning, I set up a Microsoft Exchance account using Google Sync so that I can sync my Google contacts with the contacts app on the Touch. At first you might not think this is necessary because I have access to my Google contacts through Gmail, but not with the mobile Gmail site. (I guess this another giveback to Apple from Google besides multi-touch.) However, there are some apps that will only email links with Apple contacts, so it's good to have a duplicate email account that the Touch likes. Android doesn't suffer from this problem and you can use various email accounts to send pictures, links, text, etc that you come across on the Web.
While the Moment has a slide-out physical keyboard, the virtual keyboard on the Touch works very well, and I can probably type just as fast on it.
I can easily swap documents on the Touch with my laptop using Wi-Fi, so there's rarely a need to physically connect the two. Email is the other option for sharing documents.
As far as evaluating medical apps for connected handhelds, Apple has many more, which was the tipping point for me picking up the Touch. According to Wikipedia pages for the iPhone and Touch, total sold equal 21 million and 20 million, respectively. Another thing which makes the experience of using so much better on the Touch is that everthing works smoothly. This is the advantage of buying a device in which the software and hardware are produced by the same company. Android is still clunky, and the graphics on the Touch are much more pleasing.
In essence, besides the Android phone which is always connected with Sprint EV-DO Rev A plan, and which is reasonably priced and pervasive (much more so than AT&T's 3G), I'm using the Touch as a miniature tablet computer. It doesn't have a digital camera, but that's OK. I've fallen out of favor with phone cams
