I had a Crumpler Wonder Weenie from TK Max about 2 years ago for £13, and found it great but small (I keep my U lock and lasso cable with waterproof jacket and overtrousers with me always - long story), like User. Just bought the (much) larger Crumpler Fux Deluxe for £47 inc postage from an online photography shop.
Went for the Fux Deluxe for the size and the extra full length zipped pocket (Donny Frank is the same size but less the pocket). If you end up paying about £40 anyway, may want to consider buying locally incase of any problems.
My one comment about Timbuk2 bags is the area between the strap and the flap doesn't seem as resistant to water ingress as the Crumpler design. Incidentally I don't work for Crumpler!
I have a large black timbuk2 from ebay as well. Came from someone in England, new with tags.. was £60 or something I think? Its indestructible, and very good for what I use it for. I will probably buy a small or medium as well as some point in the future, sometimes the large is just too large... its huge.
i have a Timbuk2 bag that has gone on various foreign trips... it's very good as you can batter it without worry. i did get a small rip in it when transporting large amounts of CDs. when i say large amounts i mean 'i can just about lift this' amounts.
i've just got a Crumpler camera bag... it's quite small for a 'large', but i second the comment about the gap where the straps are and the bag... the crumpler has additional flaps to 'seal' it.
i didn't know about TK Maxx... i'll have a look next time as i might be persuaded to get an XL camera bag if there's one cheap.
I don't cycle with them, but I've used Crumpler's camera bags a fair bit (using a "Loyal Chap" currently to carry a D70 + 18-70, F3/F90x + 50mm, 12-24 and various lenses/body in the lower portion. Generally weight is carried well in them (straps take a long while to feel uncomfortable, even with that weight), and the stabiliser strap (crumpler call this the third leg) works really well to stop the bag moving around while being carried.
If the messenger bags are as good as the camera bags, they'd be a good bet, imo.
Thanks for the tip on TK Maxx Punky Possum. Have been looking for a big messenger bag to carry a suit and stuff on my commute. The prices for Timbuk2 and Crumpler were ridiculous even on fleabay.
Popped into TK Maxx on the off chance today and got a Crumpler Dhardly XL for £37 rrp £125 absolutely cavernous.
I got a bagaboo. It's the tits, but expensive. Still looks brand new after two years of daily use. Also, being a bit of a saddo, it's nice to know that absolutely no-one has the same bag as me because I chose the colours and the big angry cow sewn onto the front.