KeyText is "a useful keyboard macro and Windows automation program" . It has a "macro" mode that might do what you want:
You can use its multiple clipboard
capabilities to make the gathering and
re-use of texts straightforward. And
online chat users will love the
"simulate manual typing" mode!
The manual gives a bit more details:
Macro simulates typing, at the speed
set in the Settings dialog. It is
slower than pasting, but has other
advantages. The clipboard is not used,
thus preserving its contents; and if
your word-processor has auto- correct
or auto-format capabilities, these
will be available. For example, if
your word-processor automatically
superscripts ordinals such as st, nd,
rd, th etc., this will only happen if
the method chosen is Macro.
the text appear is also intriguing,
while the KeyText icon gives a visual
clue that typing is taking place. When
KeyText is "typing" in your text, you
can abort by pressing [Esc] or by
left-clicking the KeyText icon.
It's not free unfortunately: its price is $29.95.