You don't need a plugin to do this.
You can either use <MTEntries> with the
recently_commented_on attribute:
QUOTE
recently_commented_on="N"
Display the N most recently commented-on entries. Each entry will appear in the list only once, so if, for example, a comment is posted to Entry A, then a comment to Entry B, then another to Entry A, there will be two entries displayed: Entry A, then Entry B.
or use the <MTComments> tag:
QUOTE
MTComments
A container tag representing a list of comments, either on a particular entry or in a particular weblog (depending on the presence of the lastn attribute, below).
If you provide this tag with the lastn="N" attribute, where N is the number of comments you would like displayed, it will list either the N most recent comments on the particular entry--if used in entry context--or the N most recent comments in your weblog, if used elsewhere.
Both of these are found in the
manual on Template Tags.