Biggest thing to not "lighten" but lesson would be the tupperware bowl. I bag my stuff. Yep, bag-0-salad, bag-o-leftovers, etc. Fits better too.

And, because I Do do the recycle thang - I wash out my ziplock bags and re-use several times (unless of course - and I try not too - get a big greasy lunch in my Bag-o).

Plus - I see a big nalgene container. Can't you use a smaller water bottle and put it into the bottle cage - personally by eliminating those things - you have a winner of a minor backpack there. V8 - meh - drink that at home to eliminate weight.

I seriously use a minibackpack that I have bike tool bag for mtb (grrr, main commuter down so using off-road mtb and it's seat doesn't like my standard min-trunk) - digital camera (never go without it), office clothes (leave shoes there at work), lunch (bag-0-something), spare glasses and other misc stuff - including files, paper and assorted DVD's I took home to work on from work.

No problem. I would rather have a little backpack on my back everyday rather than deal with panniers everyday - although I enjoy them - but it's more room and I would pack more stuff into them and/or a trunk and <shakes head> no!

Actually I just purchased a new camelbak with a small backpack option and I''m thinking that I can use that as my commuter bag versus my other. Just have to take the larger backpack once in a while to stock up the office (like change shoes/boots out in Spring/Fall, etc) once in a while - other than that I'm good!