Just a quick tip: If you find you are making those photo collages a lot, you might try using GIMP to edit each photo, and then Inkscape for the assembly of your collage. Name each picture in your group "pic1.jpg, pic2.jpg, pic3.jpg... etc." This way you can use the "link" option (instead of "embed"), add things like photo borders, and shadows, and then save the inkscape file as a template. Then when your new pictures come in for the next blog collage, you can edit them in GIMP, and save over pic1.jpg, pic2.jpg, etc. Then simply re-open your Inkscape template. You'll see inkscape has automatically updated your template with the new images. Just export to whatever size you need!
Be sure to post your results for us!
