It'd be nice to see your lines cleaned up; on the comic you have up as I'm looking at your site today (July 17th), for example, the lines that make up the panel borders extend beyond the edges, etc., not to mention that everything is on a slant.
Secondly, I notice that there are a number of significant grammar errors in your comic, mostly in the area of capitalization and punctuation; I know from experience that it's helpful to type your scripts out and run them through a spell-checker (human or computer).* Also, I might suggest finding a different font for your text, although my dislike of Comic Sans is rather subjective.
One last thing - with your non-coloured comics, you might want to consider converting them to greyscale. For example, in today's comic, I can see patches of blue where you've shaded in the silhouettes of the buildings.
*Ironically, I'm sure this post is full of errors -- it's late at night... ;>.>