I'm new to these forums, but this is a thread on which I might have some insight. I have a BlackBerry Curve with a program called Vlingo. Vlingo is a free text-to-speech program that can be used for a number of different things. Simply hold a side button and speak things like, "New Task: Call Mom about moving furniture on Friday", and the task will be created. That may meet your needs, as the BlackBerry also has a voice recorder for longer recordings.
Edit: Here's the link for Vlingo's website: http://www.vlingo.com/
In the interests of disclosure, I do work for RIM, the makers of the BlackBerry, in tech support, but this is what I do with my personal device. Also, a caveat with Vlingo is that it will only work when you have data coverage, as the translation to text is done by a remote server. All things considered, though, it makes task entry tremendously easier when I'm driving or cannot type.
Vlingo can also be used for lots of other things, too, like sending texts or e-mails, searching the web, updating Twitter, creating memos, et cetera.