Quite a few people have mentioned the dated, ugly look of the website. I have someone working on a possible replacement now, the front page will reflect changes before long, then we can give feedback.
Secondly, we really need a slogan. So, turning to you guys for help… suggest some slogans here.
Let me add a little ground rule to help keep this clean…the word "spank", "slap", or any other similar derivative will not be considered for a slogan.
'jME, it really whips the monkeys ass' 
Main Entry: whip
Part of Speech: verb 1
Definition: hit
Synonyms: bash, beat, birch, bludgeon, cane, castigate, chastise, cudgel, drub, ferule, flagellate, flog, hide, larrup*, lash, lather*, punish, scourge, spank, strap, strike, switch, tan, thrash, trash, wallop, whale, whomp*
darkfrog said:
Let me add a little ground rule to help keep this clean....the word "spank", "slap", or any other similar derivative will not be considered for a slogan.
Your rules, can't change them now :D
"jMonkeyEngine: Changing the Gaming Landscape one Monkey at a time."
"jMonkeyEngine: Realize Your Dreams."
"jMonkeyEngine: Furry, fast and fun"
"jMonkeyEngine: So Easy, even YOU could use it." }:-@
"jMonkeyEngine: So Easy, even FROGS could use it."
Fixed.
Okay, if we're just throwing out ideas…brace yourselves. 
"Like taking candy from a monkey…"
"Monkeys are cool" - I really don't mean that, but it might be a fun slogan
"Dream Wild"
"ooh ooh eee eeee" - stolen from Mojo
"Raaaawrrrr!"
"Adding depth to Java" - okay, that's just stupid
"Better than you are"
— From a Slogan Generator —
"You've Got Questions. We've Got Monkey."
"I Can't Believe It's Not Monkey."
"Only Monkey Has The Answer."
"Cuts Monkey Time in Half."
"Better Living Through Monkey."
"Think Monkey."
"Marvin the Mountie Always Gets His Monkey." - seriously…what's wrong with these people
"For That Deep Down Body Monkey." - just when you think it can't get any worse
"It's Good To Talk Monkey."
"Mum's Gone to Monkey."
"Bridge That Gap with Monkey."
"The Best Monkey A Man Can Get." - that just sounds gay…really
"It's Monkey Time."
"I Think, Therefore Monkey."
"From Our Monkey to Yours." - just plain wrong
"Do You, uh, Monkey?" - I almost didn't post this one, but couldn't resist
"Hands That Do Dishes Can Be Soft As Your Monkey." - I think there's a person coming up with these in real-time
"Monkey is What We Do." - Actually not that bad
"What Can Monkey Do For You?"
"What's In Your Monkey?" - maybe a better slogan for a specialized doctor. :o
"The Science Of Monkey."
"A Day Without Monkey is Like a Day Without Sunshine."
"Because So Much Is Riding On Your Monkey." - so, so, so wrong
"Wow! I Could Have Had a Monkey!" - No comment
"8 out of 10 Owners who Expressed a Preference said Their Cats Preferred Monkey." - really?
"Nothing Sucks Like A Monkey." - unless you're selling vacuum cleaners is this ever an appropriate slogan?
"Don't Live a Little, Live a Monkey."
"Recommended By Dr. Monkey." - this requires a name change for you mojo
"The Incredible, Edible Monkey."
"You're in Good Hands with Monkey."
"The Good Monkey Kids Go For."
"All You Add Is Monkey."
"The Ultimate Monkey Machine."
"When It Absolutely, Positively Has To Be Monkey Overnight."
"Step Into The Monkey."
"Monkey Saves Your Soul." - k?
"Can't Do It In Real Life? Do It On Monkey." - that's just twisted
"When You've Got Monkey, Flaunt It." - I don't know why, but this one really disturbs me
Okay, that'll do for now.
While I know those are mostly jokes (the generator especially since it's just well known slogans with monkey thrown in), some are good enough that they might be a start. I like where the following are going:
"Only Monkey Has The Answer."
"Better Living Through Monkey."
"Think Monkey."
"Bridge That Gap with Monkey."
"Monkey is What We Do."
"What Can Monkey Do For You?"
"The Science Of Monkey."
"All You Add Is Monkey."
"The Ultimate Monkey Machine."
"Step Into The Monkey."
How about: "Put a Monkey in your Engine"
I like: "Stupendously bananalicious!"
or
"By monkeys, for monkeys."
"Look at all those Monkeys! Flying!! In 3D!!1!"
Gathers said:
"Look at all those Monkeys! Flying!! In 3D!!1!"
LOL Just need to fit SFTU* and BBQ somewhere in there. :)
* Gizmodo reader here
How about "jMe, so easy a cave monkey can use it!"
Here is my share:
"jME: Awake the Monkey in you"
"Here 3D, hava a banana!"
"Climbing Tree-D"
"The Universe of the Monkeys" (Parody of planet of the Apes )
"An Engine fueled by Monkeys"
"Serious Monkeys for serious tasks"
"Monkeys invading Java"
"The Way of the Monkey"
"Have a cup of banana mocha"
Some lame… some, I'd like to think, catchy. 
For a new look, consider some of the page skins from http://www.tinyportal.net/
I'm using one of their free ones for my new site (still in development), see itsjustgroovy.com
"Serious Monkeys. Serious Engine."
"Start Monkeying Around"
"Fling your own Java"
"Monkey code, Monkey play"
"More fun than a barrel of C++"
"How do you Monkey?"
"JavaMonkey: Fresh 3d Shenanigans"
"JavaMonkey: Homebrewed 3d Mischief"
"Making java monkeyshines"
—
On another note, everyone in Atlanta I tell about Java Monkey thinks I'm talking about this coffee shop in Decatur. http://www.javamonkeydecatur.com/
And apparently there is an Atlanta band called Java Monkey, too! Strannnnnnnnge.
All that I can think of for a slogan is the Simpsons episode with a thousand monkeys at a thousand typewriters producing the greatest novel known to man.
Mr. Burns: This is a thousand monkeys working at a thousand typewriters. Soon, they'll have finished the greatest novel known to man.
[reads a page]
Mr. Burns: All right, let's see..."It was the best of times, it was the BLURST of times?" You stupid monkey.
So maybe something like,
"A Thousand code monkeys at a thousand keyboards produced the greatest 3D engine known to man"
(perhaps a little over the top)
It's probably better to keep it short and to the point.
"Pay peanuts, get Monkeys", maybe throw a 3D or a java in there somewhere too.
“Born from bytecode on a mountain top”
“Great Engine, Equal of Monkey”
“A great journey begins”
“The beginning of Wisdom”
Real geeks should get these already, but just incase
http://en.wikipedia.org/wiki/Monkey_(TV_series)