Time Marks?

I did a search here and didn’t come up with anything, so pardon the potentially stupid question.
I use the Win7 version of Audacity.
I would like to be able to tag or mark particular places within a track. This would be very useful while editing. For example, tag all the uhms or coughs. etc.
I am unable to figure this out. Is there a trick, or is it simply not something Audacity does? This one little thing would make this program near perfect.

Thanks.

Add a Label track …

http://manual.audacityteam.org/man/label_tracks.html

Can I do this on the fly as the track is playing?

Ctrl + M to add a point label (Marker) at the current play position.
Ctrl + B to label a selected region.

For more info, see: Label Tracks - Audacity Manual

or to label a selected point (effectively a region of zero length)

WC

PERFECT!
Thanks.