Where do the "var" versions of the letters come from? Just different handwriting styles?

I think the varsigma (ς) is at least a special case - it's only used when sigma is at the end of a word, is that right?

Yes, they're just different styles of hand-writing those letters. Usually they're more calligraphic-y, but for example I've always wrote \vartheta instead of \theta and my dad always writes \varpi instead of \pi. And while I just have awful, sloppy handwriting and I find \vartheta easier to write (easier to not try and hit the other end of the circle) my dad is just being posh :)

With the exception of the ς which is as you say, the form used at the end of words (I don't know why- probably something to do with ancient writing styles).

We (using the Latin alphabet) have different forms of at least lowercase a, q, w, x, z, and uppercase A, I, J, M, Z. Also the numbers 1, 4, 7 and 9.

Looking at something I wrote yesterday, I use one of the alternative forms consistently, and another only when writing my name.

> I think the varsigma (ς) is at least a special case - it's only used when sigma is at the end of a word, is that right?

Correct.

>> Looking at something I wrote yesterday, I use one of the alternative forms consistently, and another only when writing my name.

I've been known to change styles in the middle of a word, in the latin as well as greek alphabet. So much for graphology...

And thanks be to the gods for keyboards.