How to output text in the R console without creating new lines?

I would like to output a progress indicator during my lengthy running algorithms. I can easily "bubble up" a progress value from within my algorithm (e.g. via invoking a provided function callback specifically for this purpose), but the difficulty is in the actual text output process. Every call to print creates a new line, and each prefixed with [1].

Is there a way to print at different moments in time, without introducing line breaks?

To be concrete, I want to achieve an "animation" that would look like the following if observed at two different times.

0%...

...

0%...2%...4%...

Use cat() instead of print():

cat("0%")
cat("..10%")

Outputs:

0%..10%

Bah, Andrie beat me to it by 28 seconds.

> for (i in 1:10) {
+ cat(paste("..", i, ".."))
+ }
.. 1 .... 2 .... 3 .... 4 .... 5 .... 6 .... 7 .... 8 .... 9 .... 10 ..