I was looking for a poncho pattern using worsted weight yarn but all of the patterns that I come up with use bulky weight yarn. Could you use two strands of worsted weight and have the same rough guage? Would it affect the pattern in general other than texture? Thanks

Well after looking at close to every poncho pattern available on the internet I found one-- where? -- at my local Knit store in the clearance box!
It is a Ann Norling # 62 and it can be knit in all kinds of different weights and I can extend the size to fit even me a size 22.
Thanks to all of you who helped me brainstorm this whole search.
This is a wonderful site with wonderful people.
Check out this pattern it is really quite neat. Very simple but can be made up fancy with fancy yarns.

It may be too heavy, 2 strands of worsted would work out to about super bulky. But you can knit some in a sample and see what happens.

Here's a pattern generator for one. Some of hers are machine knit, but this one is hand knit.

http://www.thedietdiary.com/knittingfiend/poncho/PonchoSlimHK.html

Here's a pattern I found that uses aran weight which is about the same thing as worsted.
http://www.yarnharlot.ca/blog/archives/2004/08/07/parting_is_such_sweet_sorrow.html

Several years ago, I did exactly what you're thinking about doing. I couldn't afford that much bulky yarn (does it seem that just recently it's become more affordable?) so I substituted 2 strands of worsted. As far as I could tell, it worked just fine. I, too,made a poncho. What's there to fit, after all?! It wasn't the same gauge, but I was happy with how it turned out. I've even had requests for the same poncho as custom gifts.

I found some beautiful yarn but it wasn't worsted weight. My son found a pattern which called for worsted weight and he loved the yarn I had. I have been double stranding his cabled hoodie. The weight is perfect! I just had to go up a needle size to make it. For the first time I a did a gauge swatch. Back is done and onto the front with button holes.

Thanks to everyone for your help. I finally found the pattern I had in mind. It is an Ann Norling # 62. You can knit it in various weights and the sizes look limitless. Thanks Again Mary