Not identical, but they often look very similar.  Since the same events affect futures contracts.  Especially since it's not very far in the future.

Here's the link to the PeakOil.com chart, if it helps:

http://www.advfn.com/p.php?pid=staticchart&s=NYM^CLJ6&p=0&t=7&dm=0&vol=0&cb= 1138080214

yep, that's J6.  I don't know off the top of my head if that's April or May, but a search on CLH6 and CLJ6 would yield the answer.
Jan - F, Feb - G, Mar -H, Apr - J, May - K, Jun - M, Jul -N
Aug - Q, Sep - U, Oct -V, Nov -X, Dec - Z

April crude is about 75 cents higher than march -seasonal factors, etc (Natural gas months are very different depending on time of year, crude are very similar)

is it just me or are those letters completely without meaning?
No, it must be you. I'm pretty sure there's a "g" in February.