I am making my first pillared (is that a word?) cake this weekend. Does anyone have experience with the push in pillars? Do they really work?
Thanks!

They work very well. I have used them many times. The only thing about them is that once you put them in they have a tendency to have a gap between the pillar and the icing next to it. I usually piped a small ball or shell border around them to hide this. Cakes with the push in pillar can not be transported assembled.
http://www.cakecentral.com/cake-photo_1084413.html
http://www.cakecentral.com/cake-photo_1077993.html
http://www.cakecentral.com/cake-photo_1071933.html
http://www.cakecentral.com/cake-photo_1065623.html
Here are some examples for you to check out

Jibbies

I also use them a lot and love them! Super easy assembly, no doweling. Agree with the gap mentioned above and I do the same thing ... pipe some icing or a small flower around the base to cover the gap. Also be sure they are pushed in straight from the git-go.

Thanks. I have the Grecian White Spike ones from Wilton. I hope I can do it.

Good to see you are not using the clear plastic spikes.......those are not a good choice.
If you look at the white vs the clear you will see the bottom of the pillar is much smaller. This is where all the weight sits
For success you definately need 4" tall tiers. It's the cake that holds the pillars in place.
You only have ONE chance to push those pillars into place. If they are removed you enlarge the hole, loosing the value of the cake to hold the pillar straight
I always instructed my students to push them in about 1-2"; look at the pillar from all angles to make sure it is straight; repeat another 2" at a time until it is in.
If you use them all th e time you probably can tell so don't have to be that careful but for the 1st times it's worth the effort and time to learn how to do it right

Thank you so much for the advice. I always do 4 inch tiers so I am happy to hear you say that. I am soooo nervous. I didn't get the clear ones for that reason. They seemed so small at the bottom.

Push in pillars are the easiest to use. I don't think the size of the bottom matters that much......they are larger than dowls.

One last question (can you tell I am a nervous nellie?). My friend is picking up the cake to bring to the wedding (my schedule just doesn't permit for me to drive it to the site). The cake is for her sister. Anyway, I will have each tier in a separate box for her to assemble at the site. Should I put the pillars in for her to travel with, or let her put them in when she gets there? THANKS!

You put the pillars in. Then she can just set the seperator plate on them at the reception. Take the seperator plate & press it lightly into the top of the cake to mark exact placement of the pillars.

Thank you everyone for your advice. It makes me feel a little less nervous on this one. I wish I could be the one to set it up. : )

AI had a cake crack when I did this, this weekend. Any idea why? It was fondant covered. Used the 7 inch spikes, with seperator plates.