They could almost be rose hips with a rust disease. Did you see the flowers? I'd try the Name that Plant Forum and see if you can get better pictures of the whole plant and close ups of the thorns and any leaves.

Here is a link that might be useful: Name That Pant

Pereskia aculeata or similar?

Here is a link that might be useful:

It's a scandent, tropical, vining leaf cactus commonly called Barbados Gooseberry or Lemon Vine. Known botanically as Pereskia aculeata (syn. P. pereskia Karst.; Cactus pereskia L.) Get close to the vine and you will see thorns and the aureolas, an identifying characteristic of all cacti. Keep you eyes out this summer for light yellow, rose-like blooms. It is easily grown from seed.
Here's a link to a picture of the fruit:
http://data6.blog.de/media/172/5540172_e61bfdfc99_m.jpg

Here is a link that might be useful: Barbados Gooseberry, Lemon Vine

Thanks, Salt and Seed. I hope the OP comes back and sees your replies.