Sorry RYD.
Just click the User CP, go down to Ignore list, enter my name and click update ignore list.
Or do it HUMMJAY's lazy way.
For the reputation, click on the scale thing of the persons post of which you do not care for. For example, click on the scale on HUMMJAY's post ^, select I disapprove, enter a comment if you want, then click add to reputation.