You spend hours neatly writing by hand.
If you like the swanky paper, you may even need one of those lined pages you put behind the page, so you keep your writing straight.
You get to the end of your letter, a masterpiece, and realise that there really is one more thing you need to say.
“No worries” you say, “that is why those two little letters P.S. exist,” and in they go.
But we don’t live in a handwritten age any more. Now I type the vast majority of my letters out to people. If I have another thought, I could just click the cursor & insert it wherever I would like. But I still find myself using postscript. It hit me this morning how silly this is. Why do I do that? I’ve decided it’s one of two things. Either a) there is something about it that harkens back to the old days, in seeing this P.S. in the letter, it looks like a REAL letter & that appeals to someone who certainly remembers having to handwrite everything! b) Maybe I’m just lazy. Maybe some conventions get dragged through from one world to another just because I don’t want to lift my hand to the mouse, click the cursor & insert my sentence somewhere more useful.
That does that say about me?
Does “Postscript” have any place in the virtual world?
Tim Goldsmith 
I use the ps as well. It gives the impression that the letter is spontaneous (which it usually is) and unedited (which it usually is as well).
So stick with it I reckon.
p.s. happy birthday for next week.
hehehe – I’ve never thought of it like that, but yes, I also use PS and probably will continue to do so – agree with Al’s comments above.
I’m a massive PS bandit, I think i’ve even used them in SMSes.
I often plan to include them in advance, especially if I have something to add to an email that has nothing to do with the rest of the text, and I want to draw attention to it.
And sometimes I’m just too busy to alter the original text to make my final thought fit.