The 3G iPad and a problem with the WIFI model

I received my 3G iPad today and have had a short time to play with it.  Signing up for the 3G account is simple and only commits you to a month by month arrangement.   The only noticeable difference between the 3G and the WIFI models is a Black panel at the top of the 3G which seems to be the 3G antenna. (See Photo)

Now for the problem.  In the last few days I was down visiting my daughter and son in law to celebrate the birth of their first child and to meet the young lady.  I immediately wanted to put up a website for all those distant friends who could not join us.  My son in law and my wife and I took a lot of pictures.  We sent out tons of emails to friends and family - but some of those emails seemed to hang in the hospital's WIFI but also in the home WIFI that my daughter and her husband use (I think it is Time Warner).  When I got back to my Comcast account, the emails which had hung up - went out in a flash.  I am not sure why that happened but it was annoying.

By the way, the WIFI model goes to my daughter after I have reconfigured it for her.