When you attend a baby shower you don't want to do it for the sheer enjoyment of going. You want to do it to be helpful. And for many honorees that means that you need to be prepared to open the gifts in front of the guests.
This is your way of showing that their present is appreciated and needed.
For many this means one thing.
And the idea of opening a gift in front of everyone is a lot of effort.
Thankfully, a well mannered hostess can arrange activities that over lap with the gift opening ceremony. This includes planning fun group activities that distract sets of people at a time.
This leaves you time to go around to each person and open the gift with just them, that way you get a nice intimate moment rather than shouting your thanks across a crowded room.
You get to avoid being the center of attention (which I understand and also hate), and they still get the happiness of seeing you open their present. While you do that, like others suggested, maybe have the other guests play a game or socialize with each other?
During my girl's baby shower we had people put their names in a bowl and after every 3 presents we pulled out a name.
They got a small lotion or soap from Bath and Body Works.
It makes it fun and interesting for everyone. I did it so that my guests wouldn't get bored with me opening up stuff.
Planning activities that incorporate all of the different aspects of what you and your guests expect is important.
I think that's a more old fashioned etiquette though.
Don't short change yourself or your guests!