I would like to add a 2'x3' vinyl banner to the front of my stage to help promote my puppet troupe & website. 
Here's the stage: http://i280.photobucket.com/albums/kk182/doctort13/WMP7-31-12001-1.jpg
It's a PVC tube frame with fabric held on by velcro.

Any ideas on how to hold the vinyl (heavier than the fabric) onto the front?  Has anyone made signs for their stage/show?  What worked/didn't work?  Thanks for your help.

Hang it off the tube itself. Add some type of cord or line to the sign itself. This can be decorative or something like clear fishing line. You then add "hangers" to the top of the line you added that loops over the PVC.  A simple "hanger" can be just that. Cut up one of your wire hangers and bend it so it forms over the top of your PVC. Then bend a small loop into one end that you can tie your cord off to. Most likely it will be best to use two hangers so the sign hangs even but you could go with a single hanger at the top and the cord is also single and hangs from that. Kind of like a picture frame wire. In times past pictures often hung from the trim that went around the top of the wall. This is where I am getting this idea/look.

Rather than a vinyl banner, I had my logo (created by the ever modest Titere here on P&S) printed on the corrugated plastic that yard signs are printed on. For example, Vistaprint's large sign: http://www.vistaprint.com/lawn-signs.aspx?txi=14921&xnid=SiteMap_Lawn+Signs+(linked+item)_Signs+%26+Banners_All+Products&xnav=SiteMap&rd=1. Then I used an exacto blade and cut the logo out so that I had a sign that could support itself. So far I've just hung it from the proscenium cross-bar, but it could be propped up anywhere as well.

Here's a picture of the banner I had made today:

I am very pleased with it. 

It turned out pretty good I think!

Interesting name, hard to forget that one. I went to your website and I enjoyed your frog clip developing the voice. It reminded me of a cow puppet we used. As time went on we collected a long list of words with the ooo sound for the scrips so he could put that moo sound in as often as possible. So for -oam sound for your frog here are a few words he could use: home, roam, nome (alaska), comb, dome, foam, moan, loam,and in a pinch poem.
Best of luck to you, like what you are doing.

Thanks for the thumbs up everyone.  I hope to get a few photos of the new banner on the stage during our big show next Saturday on Fountain Square, which is Cincinnati's version of Times Square.  Take a peek:  http://myfountainsquare.com/

Here are a few photos of my show, there are more on my Facebook page.  Thanks for your interest:
https://www.facebook.com/media/set/?set=a.460798937276857.102163.108119109211510&type=3

Turned out pretty good. I like how you bunged the bottom down so it would not blow up.