If you want to post a link to a specific post its quite easy (thanks jeffro for making this obvious for me)
Every thread has a general URL which will take you to the top of Page 1 for that thread eg
The key to linking to a specific post is to identify that post number and replace it over the top of the last bit of the thread URL after the #
Note that you also have to change the page number to the page matching the post you are linking to.
Identifying the post number is easy - mouseover the 'edit post' icon and look for the post number at the bottom of your browser window - it will reveal the URL including the post number - naturally you wont be able to edit someone elses post so dont bother clicking it unless you like getting error messages.
Hope that helps!