tgriesser's questions

I am looking to setup a TXT spf record that has 2 included domains... individually:

v=spf1 include:_spf.google.com ~all

and

v=spf1 include:otherdomain.com ~all

What is the proper way of combining them into a single item?

I have a subdomain of a site, lets say foo.example.com which has an A record to the IP of another server, lets say example2.com. Ideally, I would like to have the example2's server also take care of the MX record for the foo.example subdomain, but I'm not sure how this would work.

I'm wondering what the options are for doing this, whether this will work:

example.com DNS:
    foo   A    xx.xx.xx.xx
    foo   MX   mx.example2.com

example2.com DNS:
    mx    MX   mx.thirdserver.com

Or could I set up a new dns zone on the example2 server which would just handle the MX record for the foo.example.com domain, where any mail sent to foo.example.com would be handled by these mx records.

Or, alternately, should I solve this with a cname or dname record

What are some good modules or systems that for caching that I can use for decreasing my load on Apache on an EC2 server running PHP, and why would you choose them?