What are these things on my oak tree?

http://i55.tinypic.com/9tmlia.jpg
What are these things and what should I do?
Thanks in advance CraigT
__________ Information from ESET NOD32 Antivirus, version of virus signature database 5412 (20100831) __________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 8/31/2010 2:44 PM, CraigT wrote:

Galls. Plenty of stuff on net about them.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Some kind of gall. They contain the larvae of an insect, usually some kind of wasp, and sometimes the adult too. They're pretty impervious to chemicals in there. I wouldn't do anything, honestly.
Chris
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.