I have a similar plant to Holden Caufields', but the plant itself is more 3 sided than roundish, anyone know what it is?

Is it possible to post a picture of it so we can get a better idea ?

Yes, I hope you get this photo/Users/stephan/Pictures/iPhoto Library/Originals/2011/19-Sep-11/Photo 1.jpg

This looks close to what your holding but has no leaves showing.

Acanthorhipsalis monacantha

You can view it here. It says it comes in a 3 sided version.

Ref:

cactusshop.com (http://www.cactusshop.com/library/products.aspx)

http://www.nationaltropicals.com.au/media/PDF/Triangle-Cactus.pdf

http://bloomiq.com/african-milk-tree

http://www.desert-tropicals.com/Plants/Euphorbiaceae/Euphorbia_trigona.html