I am considering taking my laptop just to stay in touch with family at home via email. It appears Carnival offers packages in 30 and 60 minutes. Since I plan to only check email once a day I  am thinking the 60 minute package should be more than enough, but was curious as to what the connection speed is like. Any information suggestions from past experieces is much appreciated.

 My experience is not from the Holiday, but I'm willing to share since no one else has.  I was on the Conquest last December.  I bought a 60 minute package and checked my e-mail daily.  It was probably a little more than I needed for a 7-day cruise, but I ended up going over a little because I spent the first day trying to connect and post to a cruise or travel forum.  It would not let me connect to any forum, no matter what I did. 

E-mail was no trouble, however.  Regular web-based email was fine.  It's faster than dial-up, but not as fast as DSL or Cable.

Do they have PC's on board to check e-mail et al., while on cruise?

Most ships (if not all) have PCs available to check email, etc.  The Holiday deck plan shows the "Cyber City" behind Doc Holiday's on the Promenade Deck. Sometimes, they're really buried on the ship and very hard to find.  But they're there.  (On the Conquest, you have to walk all the way through the cigar bar to get to it.  There's no other entrance from anywhere.)  Just ask a staff member once on board and they'll direct you to the right place.

Hello! I just got back from the Mobile to Cozumel jaunt on Holiday. We used the internet one night. It is located in the Carnegie Library, which is on the 8th deck (or 9th, I forgot) near the Four Winds dining room. Cyber City is the arcade. They have several computers for public use, and you just log in using the info it prompts you to use. They charge a first-time account activation fee of $4. We didn't do a minutes package because we didn't think we'd use many minutes, but we ended up spending $44 and regretted not getting a package. Oops. The speed was was slower than most of us are used to, but not toooo bad. I would guess it was about 3 times slower than my home internet, so account for that when you decide what to get. I heard that you could bring a wifi-enabled laptop anywhere on board, but I didn't see anyone doing it so I didn't hear any feedback about it. Hope this info helps!