Second, how do you do a speech bubble? I don't have Photoshop and use a Mac.
Let me throw you a bone there, Brendan. There are many open-source and free graphics editors. A very powerful one is GIMP (which has Windows, Mac OSX and Linux versions). That would get you started.
My fear is that by giving you these tools, it will probably start a trend of you captioning all of your photos with thought bubbles.