First of all, for all of you wrestling with the thorny problem of whether to join the church of Steve and get an iPhone or join Ms. Palin in going rogue by plumping for a Droid, check out the xkcd comic strip on the topic. Brilliant!

Anyway, it seems the problem I posed in a recent column about how to get an Excel spreadsheet to randomize the numbers from 1 to 75 is still generating comments.

In response to the final and most elegant solution that I discussed a couple of weeks ago, one reader noted that should two identical random values be generated the spreadsheet will fail and, indeed, that is correct except it shouldn't happen.

Remember that the random number generator in Excel is actually a pseudo-random generator. The formula it uses creates a sequence of values to 15 decimal places that, according to Microsoft, doesn't repeat for at least 10^13 generated values. Given that we're using 75 values per recalculation of the spreadsheet, if we did a recalc once per second it would take something like 42,280 years before we'd get a repeat. I'd hazard that's good enough for everyday purposes.

Now, talking of everyday purposes, how often do you break out a tool like Visio? Probably fairly often if you're involved in any kind of planning or systems design work, and it is definitely a very good program except for one thing, at $559.95 for the full version of Visio 2007 Professional, it's rather costly. If you are averse to being absorbed by the Borg, you might be inclined to look for alternatives.

An interesting way to go might be Gliffy, a Flash-based, SaaS-style online diagramming tool. It supports templating (a basic set of 10 templates is available), printing, saving to Gliffy's storage, exports to SVG, JPEG, and PNG formats, and most of the other basic features of Visio. You can also share your diagrams online with other users and or post your diagram to a blog.

Click to see: Gliffy screen shot

While Gliffy is admittedly fairly limited compared with Visio, it does provide all of the basic facilities and only a real power user would need more. That said, the big advantage of Gliffy is it is priced right starting at $5 per user per month (volume discounts drop the price to $1.75 per user per month for 1,000 users).

But let's say you want to keep it all on your desktop rather than out in the cloud and or you want more features. If you're on a Mac then Omnigraffle 5, ($199.95 for the professional version) is outstanding! This is a remarkable program with a huge feature set and AppleScript programmability.

Click to see: Screen shot of Omni Graffle

For those of you who eschew OS X might I suggest you take a look at SmartDraw 2010 Professional. At $297 SmartDraw 2010 is normally about half the price of Visio 2007 Professional and until Jan. 12 it's on sale for $197. W00t!

SmartDraw's feature list is really impressive, including as it does some 1,900 templates compared with Visio's 150, a really amazing automated flowchart creation subsystem, integrated photo support, ability to import Web page images, and a whole slew of automated diagrams that include mind maps, interactive maps that are extracted from Google Maps on the fly, project charts, decision trees, graphs, and charts. It also has really great integration with most of the Microsoft Office applications including Visio as well as with SharePoint.

Click to see: Screen shot of smartdraw

A feature of SmartDraw that I love is you can create charts that can be loaded directly from SmartDraw into PowerPoint and automagically animated! What SmartDraw does is let you choose animation options such as building a bar graph by data points or by categories and then creating the PowerPoint custom animation steps so that with each mouse click the graph incrementally builds.

The only feature that SmartDraw lacks compared with Visio is it doesn't support programming, but given that Visual Basic for Applications (VBA) is pretty horrible to work with and that I doubt whether many people bother to automate Visio to any serious degree, I think that's perhaps not a huge negative.

The only significant problems I have had with SmartDraw so far: under Windows Vista Ultimate the SmartDraw installer wouldn't let me install the program anywhere other than C:\SmartDraw 2010\ (it claimed all other locations were invalid); and to import Visio diagrams Vision has to be installed. Other than that, SmartDraw 2010 works excellently, creates great looking diagrams, and is excellent value for money.

I award SmartDraw a rating of 4.5 out of 5 – to get the other half point I'd need to see programmability (Python or Ruby would be great choices).

Gibbs has it sketched out in Ventura, Calif. Draw him in at gearhead@gibbs.com.