I’m in process of changing from the Network solutions DNS servers to the DNS servers at Zoneedit. The main reason I’m doing this is to gain access to the TXT DNS record so that I can put up my own SPF entry.
Hopefully this will not impact the site while I am transferring everything. I’ve done this 1,000 times but I still seem to screw things up once in a while 
I’m also hoping that the Zoneedit DNS servers will be a bit faster
Once I’m done with this transfer I’m going to be transferring a lot more domains and adding the SPF records and then changing them all from Network Solutions to GoDaddy.com (I was in process of doing this well before the super bowl ad …)