I Missed the start of this... but... last year I used 28mm (approx) focal length in my PotD for 48 days straight with just 4 exceptions. I chose 28mm (a 'normal' lens on the 300D: 28mm is approx the diagonal mesurement of the sensor) as it's a difficult focal length to use. It lacks the drama of wide angle and the punch of telephoto lenses, and images can look a bit too, well, normal. You have to work hard with a normal lens, although, if I had to use just one lens forever, that's what I'd choose. That's why years ago, students of photography would use a K1000 with a 50mm lens - approx normal for 35mm cameras. If you can master a normal, then everything else is easy. It was lots of fun, and it really stretched my creativity.
My 48 days started <a href="http://www.pbase.com/vid64/image/31486729">July 18th</a> and finished <a href="http://www.pbase.com/vid64/image/33373864">September 3rd</a>.
Some examples:
D