Everyone likes messing around with images, so why not let Meteor have some fun with it. This Meteor Smart package is built on Aaron Heckmanns gm for Node. This package also includes an import to the Node Path directive, allowing you to easily access the local path of the Meteor app (helps a great deal with GM's absolute paths).
Get yourself set up with
mrt add GraphicsMagick
Then within your server code (GM is only applicable server side) define a variable to store your applications working path, using the included path library
var __dirname = path.resolve('.');
Then use GraphicsMagick as you would the NodeJS version.
// resize and remove EXIF profile data
gm(__dirname+'/public/nonrefresh~/img.jpg')
.resize(240, 240)
.noProfile()
.write(__dirname+'/public/nonrefresh~/img_thumb.jpg', function (err) {
if (!err) console.log('done');
});