I do them all the time... it is one less thing in my kitchen making a mess, many are really cute and interactive and it is easy to respond. I hate calling to rsvp especially for something like a shower when I don't know the host.
I don't think so, I did them for J's baptism and it was definitely easier. I would just maybe do a couple of regular ones for people that don't do email, or one to keep, or for the grandparents, etc.
Although if you go the regular invite route, my sister and I were just talking invites yesterday and you can do a photo card through seehere.com with a promo card and get 20 for $1.49 shipped.
We did it for his 1st birthday party - forget why we used it, but it worked out really well. If they weren't sure how to respond, they'd just call or email us. I think they're fine for things like birthday parties or get-togethers. Don't think I'd use it for a formal event, like a wedding, but wouldn't begrudge anyone if they did.
abba916:I think they're fine- I considered using them but I invite so many older family members I might as well just do print invites...
This for me too. And I like to keep one for the baby book. But I don't think they are tacky at all.