I'm a big fan of iWorks myself and I too made the big transition from Microsoft Office to iWorks a few years ago. Just went cold turkey. I admit, there were some hiccups, particularly since it was the first generation of iWorks I was working with, but other than some compatibility issues with Keynote vs. PowerPoint, it's gone smoothly.

I rarely have to sort data in Pages documents myself but I created some sample text so i could check out what you were talking about and darned if you're not right. There's no easy way to sort text in the program.

There is, however, a trick...

Turns out you can indeed sort text in Apple Pages by converting the lines to a table, sorting the table, then converting it back into text. Let me show you.

Here's a sample of a dozen or so lines, my frequent flier accounts (all slightly tweaked for my own privacy, in case you're curious):

Select all the lines by using either "Select All" or just click and drag to select them all. I used the context menu accessible from a control-click:

With the lines to sort selected, we need to choose "Convert Text to Table" from the "Table" menu under "Format":

Once that's done, the information will be shown in a one column table format:

That's the hard part done. Now, time to sort the table. You need to launch the Inspector window and get to the "table" area, then you'll see a small 'gear' menu under "Edit Rows and Columns". Click on it:

That's the only place I can find any sort of sort capability in the entire program, but it's good enough! Choose "Sort Ascending" and the text in the table is sorted as we'd hope:

Last step, time to switch the table data back into regular text. Do that by selecting the entire table (click and drag the text to make it easy), then choose "Convert Table to Text" from the "Table" submenu off the "Format" menu:

And the results?

Is this a ridiculous pain to accomplish in a program that should include a "Sort Selected Text" option? You bet it is. Meanwhile, it's better than nothing and perhaps in the next update to iWorks we'll see this feature added.