I, after a few moments of doubt, decided to give the beta (and therefore free) trial of T9 Nav a go. T9 Nav is made by the same company - Nuance Communications - as T9 predictive text itself, and starts there. It's essentially a desktop search tool, for those of you who are familiar with that notion, and what it does is give you fast access to (theoretically - caveats apply) all content on the phone, from the home screen. It handles the fast part by building an index of all applications, bookmarks, documents, media files etc. This sounds scarily as though it'll bog the phone down and make it run at a crawl, but only takes a few seconds while you watch.
The cool part is how it handles the access part. Simply start typing, using normal T9 rules, and voila! A list of all matching content will be displayed upon the screen. If you are dialling a number, simply ignore the results, finish the number and hit dial. It learns, too - just like a proper implementation of T9, the results you select most often become favoured and are put at the top of the list.
This works so well, it's amazing. I admit to skepticism to begin with, but colour me a convert. The first advantage will be obvious to anybody who has used an S60 phone - it bypasses a messy and faintly arbitrary menu structure and goes straight to your result. But it also taps into an existing (assuming you have it) skillset, using automated and therefore rapid text entry instead of a clunky menu-up-left etc. selection.
For example: To get to MobiReader in my heavily customised menu structure, I could enter Menu-down-select-down-select-select, and that can only be done smoothly through repetition. Or, I could type mob(662)-down-select. Now which one seems easier to you? Finding the unit converter, which I have used a couple of times lately but have no idea where it lives in the menus, would take of a fair few seconds and a bit of head-scratching (is it in the Office folder??), or I could just do conv(2668)-down-select.
Okay, it's not perfect. Yes, it is still in beta and it does have issues. Several commentators have mentioned that it doesn't seen to index the music player, but I have noticed that neither does it index Sync, nor index text files, such as this one, and I still have to go through a file browser (yes, I'm compiling this on the phone).
At this point, I have to admit that it's not unique, and that the company responsible for T9 doesn't even seem to have been the first to think of this implementation. If you want a program that isn't still in beta, try the ludicrously named SkyeQuiKey from SkyeStream. These people have obviously never struck upon the idea of product names that are easy to google for. SkyeQuiKey is not free - and I'm expecting that when T9 Nav comes out of beta it'll no longer be free either - and although there is a trial period, it's the amazingly useless 1 day.
I'm sticking with the free T9 Nav until it tries to charge me for it. At that point, I will be hard pressed indeed to not shell out for it.
Link to T9 Nav website
Link to SkyeQuiKey website