Over the last five years I have been gathering gear for my survival/day kit. I planned to use a G.I. butt pack to stow it in, but I've found that it's too small to stow the gear I need. I've surfed the net but it seems there's nothing intermediate between a day pack and a medium Alice pack.
Any advise? I'd like to get something good but not too pricey and not too big.

Maybe one of the small backpacks that kids use to haul around their books & stuff to & from school.

Maybe a small cotton canvas rucksack like this, that you can find in surplus stores and thrift stores. No breaking zippers, extra cordage from the fastening cord at the top. You waterproof it with a small dry bag liner or something.

This one is worth a look. The big advantage is a real, functional, internal frame that transfers the load to the hips efficiently, meaning you can carry serious weight comfortably, if need be. However, it's volume is more like a large day pack. It is also very adjustable for size. It doesn't look too "tactical" and blends in like an ordinary day pack, especially the "civilian" colors. It's $100 with free shipping, which may be over budget, but it is listed elsewhere at over $170, and well worth it. I own two; one is for deployments, the other is my BOB/travel/day hiking pack, and I'm very happy with them after extended use. Kelty MAP 3500

* 1950 cubic inch volume
* 420d HD nylon Oxford mesh cover on back panel and shoulder strap
* 420 gram, 100% nylon Airmesh EVA foam in back panel and shoulder straps
* 500 denier nylon Kodra (1000d on ACU color!) construction, double stitched
* Internal suspension, two fit to form Light-Beam stay rods
* Panel loading pack, single large compartment 2 exterior zippered pockets
* Interior hydration pouch, supports up to 100 oz. bladder, 210d nylon ripstop
* Hydration port at top of pack allows for drink tube to be used over either shoulder.
* Hydration port has snap on top flap closure
* Exterior cargo pocket with fleece eyewear pocket and admin organizer pocket
* Side mesh pockets (fits 1 quart lexan water bottles each side)
* Waist belt (removable) with Scherer cinch system, with waist belt tuck-away feature
* Adjustable sternum strap
* Fully adjustable (removable/replaceable) shoulder straps

I own the Mountainsmith Approach 3.0 daypack. I have had it for a few years and love it. I like the pocket configuration. In addition to the main compartment, it has two vertical side pockets, a front pocket, and a verticle front pocket. It has a pocket for a hydration pack and two outside pockets for water bottles that are canted forward so you can remove and replace your water without removing the pack. There is an expandable space between the front pocket and the main pocket . There are straps across the bottom so you can lash on a sleeping bag or your jacket. Daisy chains on the shoulder straps and the bag itself to attach more stuff. To top it all off, the sternum strap has an integrated whistle.

Oh, and customer service at Mountainsmith is fantastic. I broke the hip belt latch by shutting it in my trunk. When I emailed Mountainsmith asking where I could buy a new one, they sent an e-mail back saying that one was in the mail. It arrived a week later, no charge.

Great bag, great service.

You may want to consider two of the large mountainsmith lumbar packs (mountainsmith stuff in my experience is very high quality/good value). The two lumbar/butt packs are the "day" and the smaller "tour".

http://mountainsmith.com/products.asp?subCategoryId=3&categoryId=4

You can get them cheaper then price listed on their site - I got both of them on ebay a few years ago. The bigger one is the "day" and it holds ovver 850 cubic inches.

For REALLY high value in a day pack, get the $40 LLBean "classic continental rucksack". One big compartment, three side pockets, everything excellent quality. Holds 2000 cubic inches. Very versatile - I love mine. Just a great bargain with many uses.

Reviews on the LLBean website.

http://www.llbean.com/webapp/wcs/stores/...8-sub2&np=Y

Here's another option.

That pack looks great. Bookmarking the website right now. Thanks for mentioning it, Jeff.

Through the years I've found two GREAT products from L.L. Bean:

One is the Bigelow Day Pack. I have an earlier version than the one currently sold, and I really like it. Its my "Scoutmaster" pack that carries all sorts of gear during Scout events. Its lasted amazingly well over the years. Note that it even comes with its own self-stowing rain cover - kewal!! Its also real important to me that it comes in two sizes since I'm taller than most folks (6'5"). They say it was identified as a "best buy" by Backpacker magazine last year. I'd agree.

BTW, the other product from L.L. Bean that I really like is their All Leather Gore-tex Day Hikers. I wear them almost every day and they've been very comfortable and have been noticeably more durable that any of the boots I've tried in years past. Highly recommended!!

Added Note: If you search the L.L. Bean site using "Bigelow" you'll find that they are selling what might be last year's model for only $60. That's a great deal.

I would guess you are looking for something around the 40 litre volume mark for a intermediate size.

One of the packs from the Karrimor Sabre SF range would most likely fullfill your requirements

http://www.pri.uk.com/ksf/index.html

Perhaps the Sabre 45 would suit. It also has the additional flexibility to add additional 12.5 litre side pockets to take the total to 70 litres capacity.

http://www.raymears.com/Bushcraft_Product/293-Karrimor-Sabre-45/

I would also recommend the Cross Bow system from Lowe Alpine as I still use a Lowe Alpine Contour Crossbow 50 and the Lowe Alpine Crossbow 65+ Expedition pack (which are now unavailable ) if you can find a retailer. These packs are very stable and comfortable.

The Berghaus Bioflex® back system gets good reviews being exceptionally comfortable and again gives a stable load carry although the C7 Bioflex® 65 + 10 Backpack might be a little to large for your requirements;

http://www.outdoorsmagic.com/news/article/mps/UAN/3098/v/1/sp/

http://www.nevisport.com/detail.asp?StoreID=0&Depth=1&ProductID=404002