Error: Access is denied. Verify that either the Default Content Access Account has access to this repository, or add a crawl rule to crawl this repository. If the repository being crawled is a SharePoint repository, verify that the account you are using has "Full Read" permissions on the SharePoint Web Application being crawled.

If you get this error in your Crawl search log then the problem is directly related to the infamous loopback Issue as described below.
You can also read more about this issue on another post located here: http://blog.dafran.ca/post/2011/07/04/Cant-log-into-SharePoint.aspx

The OFFICIAL Microsoft KB article describes the 2 different ways to resolve this issue.
http://support.microsoft.com/kb/896861

The following is copied from the KB link above.
There are two methods to work around this issue, use one of the following methods, as appropriate for your situation.

Method 1: Specify host names (Preferred method if NTLM authentication is desired)

To specify the host names that are mapped to the loopback address and can connect to Web sites on your computer, follow these steps:

1. Set the DisableStrictNameChecking registry entry to 1. For more information about how to do this, click the following article number to view the article in the Microsoft Knowledge Base:
   281308 (http://support.microsoft.com/kb/281308/ ) Connecting to SMB share on a Windows 2000-based computer or a Windows Server 2003-based computer may not work with an alias name
2. Click Start, click Run, type regedit, and then click OK.
3. In Registry Editor, locate and then click the following registry key:
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\MSV1_0
4. Right-click MSV1_0, point to New, and then click Multi-String Value.
5. Type BackConnectionHostNames, and then press ENTER.
6. Right-click BackConnectionHostNames, and then click Modify.
7. In the Value data box, type the host name or the host names for the sites that are on the local computer, and then click OK.
8. Quit Registry Editor, and then restart the IISAdmin service.

Method 2: Disable the loopback check (less-recommended method)

The second method is to disable the loopback check by setting the DisableLoopbackCheck registry key.

To set the DisableLoopbackCheck registry key, follow these steps:

1. Set the DisableStrictNameChecking registry entry to 1. For more information about how to do this, click the following article number to view the article in the Microsoft Knowledge Base:
   281308 (http://support.microsoft.com/kb/281308/ ) Connecting to SMB share on a Windows 2000-based computer or a Windows Server 2003-based computer may not work with an alias name
2. Click Start, click Run, type regedit, and then click OK.
3. In Registry Editor, locate and then click the following registry key:
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa
4. Right-click Lsa, point to New, and then click DWORD Value.
5. Type DisableLoopbackCheck, and then press ENTER.
6. Right-click DisableLoopbackCheck, and then click Modify.
7. In the Value data box, type 1, and then click OK.
8. Quit Registry Editor, and then restart your computer.

I hope this helps someone out there!