EditPad Lite has a nice feature (CTRL-E, CTRL-I) which inserts a time stamp e.g. \"2008-09-11 10:34:53\" into your code.
From the Vim Wikia.
I use this instead of having to move my hand to hit an F key:
:iab tds strftime("%F %b %T")
Now in Insert mode it just type tds and as soon as I hit the space bar or return, I get the date and keep typing.
I put the %b in there, because I like seeing the month name. The %F gives me something to sort by date. I might change that to %Y%m%d so there are no characters between the units.