Mobile Office 2010: Free, and worth every penny
Download relief for the WinMo 6.5 ghetto denizen
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Microsoft Office Mobile 2010 is now available for those using Windows Mobile 6.5: a nice enough upgrade considering it's free, but you wouldn't want to pay for it.
Office Mobile came out as a beta last year, but now is available from the Microsoft Marketplace, bringing SharePoint Workspace and remote control of PowerPoint presentations to Windows Mobile 6.5. But you still can't create new presentations and it won't underline your spelling mistakes in red, so not a desktop replacement just yet.

TextMaker on the right: more functionality but at the cost of performance (and money)
Word Mobile is admirably fast, and manages to display most in-line images and embedded content, but compare it to a real word processor (TextMaker from SoftOffice in this case) and the difference is manifest - not only will TextMaker check spelling on the fly, but notice the track-changes/comments ribbon. Such things don't exist in Word Mobile, at least not until Windows Phone 7. Microsoft is pushing the concept hard there, as demonstrated in this video from MobilityDigest:
That video also shows a new interface for SharePoint; the version that comes with Mobile Office 2010 isn't nearly so pretty, but the important functionality is there.
Pocket PowerPoint still won't let you edit presentations, though it will show them, and link up to a desktop to allow the phone to be used as a remote control.

For reviewing your slides, not creating them
Given that Windows Mobile is effectively dead it's surprising to see any kind of upgrade being made available, though we'd hope the majority of the package will end up as part of Windows Phone 7 - just with a prettier interface. ®
COMMENTS
As far as I'm concerned...
..they're all shit. Inevitably; because you're trying to do things on a tiny screen with a wanky little stylusy thing. It's all Sirus Cybernetics Corporation stuff - the satisfaction gained from getting it to work serves to hide the fact that it doesn't do anything useful.
Want to know how much time you've spent typing in a few words with a stylus which would have taken a few seconds on a computer? There's an app for that.
[braces self for flood of posts about how marvellous they are]
You left out Maemo/MeeGo
You left out Maemo/MeeGo, which is a shame, because it can OpenOffice and KOffice perfectly well, *right now*.
I've tried
To explain and convince many customers that they can edit word or excel files on their WinMo/Blackberry/Iphone.
And almost everyone said that the only use of word and excel on a smartphone is to have a quick look at attachments to see what the file is all about. They will open the file later on their computers and read it properly. Everybody says the screen is too small to work or read with any comfort.

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