Mexco Energy Corporation (MXC)

[littlefish]

Here's another link showing how nat gas as a source for powerplant fuel is worthwhile compared to coal with nat gas prices in the $7 range. This company has proven to be fairly profitable even with nat gas prices in the $6s-$7s.
Of course if nat gas prices go much higher, it becomes less cost effective for nat gas. But that would mean better profit marigns so there's some balancing:

http://pepei.pennnet.com/Articles/Article_Display.cfm?Section=ARTCL&PUBLICATION_ID=6&ARTICLE_ID=313198&C=Depar