Well, I’m either going to be getting a 13.3" or a 12.1" laptop (depending which I go for) and I’m struggling to find any decent tests for the smaller laptop bags.

Being an avid viewer I was using the Gadget Show's test as a guide, but all of them are for 15.4" or above.
http://gadgetshow.five.tv/jsp/5gsm [...] n=Features
Of the 5 which survived their insane testing (water, impact etc.) the only one I like enough to buy is the Pakuma K3lt, cheapest here (http://www.scan.co.uk/Products/ProductInfo.asp?WebProductID=728446&source=froogle).

However that will still be quite big, so I looked at the rest of their range and saw the K3s (http://www.pakuma.com/products/choroka_k3s.htm) which is for up to 13.3" laptops, so if I get the 12.1" one it won’t be a really tight fit. However I can’t find any proper reviews on it where it has been tested! The only one I know to be really good is the larger version.

Anyone know of any other messenger style bags that are weatherproof (I live in England...so I get rained on a fair bit!) and tough...and preferably made for a 13.3" laptop...I’m not being that picky!

Thanks

I've been a big fan of the laptop backpack-- all the ones I've owned have had rain flys (first from Performance Bike, next from Gap (I broke the zipper), and my current one: a High Sierra Access). I used these for school and work.

I know you were looking for a small one, however, the ability to carry everything (even a change of clothes, including shoes) in one tote is quite convenient, and unlike the traditional laptop bags or the messenger bags, the backpack distributes weight more evenly and comfortably.

EDIT: posted this before i was done. . .

Anyway, if you want small, there's the Crumpler Salary Sacrifice (yes, it costs). . .
The Osprey Torque transit is not small, but it is TOUGH and pertty good with the wet, as the Nantahala Outdoor Center (whitewater outfitter) sold them for a while

I know there's other stuff from Kensignton and Targus and the like, but if it were me I'd stick to companies that are primarily outdoor recreation companies than computer companies.

Yeah, ive used a backpack for the last 13 years at various stages of school and collage! However i like the ease of a messenger style bag.

Although, that Crumpler does look good...and at $130 thats roughly £60 which isnt too bad at all, its very similar to the pakuma one! Im also not too worried about the price (within the extremes of course!) as i dont want to risk a £650 tablet! However the padding isnt meant to be that great around the laptop...where as the Slappa Spyder V2 backpack (http://www.slappa.co.uk/index.asp? [...] &ProdID=59) came second in the gadgetshow tests which means it took a total soaking and had various heavy objects dropped on it and still the 'laptop' (actually they used plates!) survived uncracked! It is, however, big, but as you said that can be useful...especially as i will probably end up crashing in somebody's halls some nights (instead of travelling home in the early hours of the morning blind drunk!) so a change of clothes would be nice!