If you are interested in a topic on the forum, you can use the Notify option to receive emails when a new response has been posted:
(http://www.pointcloud.us/files/uploader/1/Notify.jpg)
Simply open the topic you are interested int and select Notify. The next time that a reply is posted to this topic, you will receive a notification email with an easy link directly to the post. This is a great tool to use after you have asked a question. There is also a unsubscribe link in every email, so can turn off the notifications very easily.