Where did you get that picture, Captain Murdock. I've seen it with Kirk or Spock alone, but never the "big four". Must have copy.
This: http://www.artofvfx.com/AVENGERS/AVENGERS_WETA_VFX_09.jpg Spoilers for the Avengers for those who haven't seen it.
Sorry for the late answer. The one I've got is 1290x1000, and I've got it from the IDW forums, I'm afraid they haven't offered variations of it. I've tried blowing it up to 1600 width and cutting tops and bottoms to get a 900 heighth. I could send it to you via PM, if you're interested. Can't tell if they picture's hurt by the enlargement, though. And while you seem to be in a mood for supreme superhero teams at the moment, so am I.
That's ok. Just send me the original and I'll fiddle with it. Even if I can't make a wallpaper out of it, it's still an nice picture to have. JLA/Avengers, nice . I love those kinds of images.