I have been fiddling with Ultra Hal for a few days now and thought I would share my observations.
First, as a chatterbot Hal is really quite amazing. Certainly it is not difficult to remember that I am just chatting to a machine, but as far as these go (and for the limited time I've been using it) this one is really well done.
As far as being a desktop assistant. I have not yet had the chance to use voice recognition (though I am excited to try it out) but the recalling of phone numbers and events seems to be kind of hit and miss right now. It is handy that you can edit the events calendar yourself though and from the help menu it looks like you can do the same with the phone book though that option does not appear in the menu of the free trial.
Opening programs also seem a little hit and miss. If the program name is simple, it seems Hal can do it. If it's a little more complex he is generally unable to do anything with it. If there happens to be a website link in the named program's folder, hal invariably opens that instead.
Given all of this, I can certainly see the amazing potential of Hal. It's what I always dreamed a computer could be. At the same time, for Hal to be of real, immediate use I would humbly suggest a few additions; Most importantly allowing Hal to import address book info either from email clients directly or manually through an exported address book file (most of the common clients easily export a standard file for this.) I would think it quite essential for Hal, as an office assistant to be able to do this. Email clients have been using these kinds of standards for quite some time now.
As with the address book and the phone book, you should be able to manually edit a program list for Hal so that, if he is having difficulty finding a particular program you would like him to run, you can specifically enter the full path of the .exe in question as well as enter in a standard real language phrase that Hal would listen for as his cue to open that program (much like you have with the phone book editor).
You seem to have hall set up to access US weather, providing a generic link field that would allow Hal to access weather and/or news from user-defined sources would also be very handy.
many of these features really ought to have been standard on Hal from the start and adding these, I feel, is quite essential if Hal is to be anything more than an entertaining toy. I would definitely consider purchasing Hal if I knew that these things would find their way into my purchase very soon.
Just my $.02