Guessing you're having this shower at work? I'd decorate the 'break room' or whatever, w/pink or blue - (if baby's gender has been determined) helium balloons that will float to the ceiling, and on each string hang a cigar OR candy cigar. Scatter baby confetti and little rubber ear plugs around the refreshment table, along with a few "new baby" magazines, maybe a bottle of Tylenol PM. If you need a centerpiece, use a Pamper, propped open (like a bowl) and filled with either a plant, flowers, or candy, and tie one or two of the balloons to secure in the Pamper.
I love the idea of a shower for a new dad. Have fun!

We've done this at several places where I've worked before. But, we invited the mother to be to attend along with the father. So, it actually became more like a traditional baby shower, but with no silly games out of respect for the father ;) It was nice because we all got to meet the wife of our coworker.

Of course invite the mom. Candy cigars are a great idea.

If you know the baby is a girl, a copy of the song Daddy's Little Girl would be nice. It would be the last time he gets to listen to it without tears. And maybe he would be one of the few guys who actually hear it before his daughter's wedding.

My DIL recently had two showers for their expected baby boy. After those, I sent my son his own gift box for their baby. I sent 4 Reds onesies in sizes 6 to 24 months.(My son is a huge baseball fan). I included a little outfit that says "Daddy's Little Boy" on the front. Kohl's has a nice set of stuffed animals/books/CDs that are only $5 apiece (some money goes to charity)and I got him a set, noting that this music would be replacing his CDs in his car soon. I also bought a couple books, including one called "One Baby Boy" and a couple that were favorite read-alouds when he was small. I really had fun assembling this, and my son seemed very pleased to have received it. I love these old threads...hope you don't mind my resurrecting this one.

Aside from playing the "measure the toilet paper around the stomach game", I'm not really sure you'd have to change anything. I'd do the same you do for the females that are pregnant in the office. I'm not even sure you have to invite the mother (although it would be nice) unless you usually invite the father's to the woman's showers in your office. Again, just do as you normally would. The fact that he is the father shouldn't really change things, IMHO.

I agree with carla35 completely.

It's been 5 years since whazzup wrote, "no silly games out of respect for the father." I hope things have changed enough since then that people no longer think that what is considered good enough for women is considered disrespectful to men! If a game is silly, then it's silly irrespective of sex.

I don't even want to KNOW what "the 'measure the toilet paper around the stomach game'" is!