I hope someone is more creative/innovative than I am, but perhaps a set of vertical bins, on wheels, to store recycling and, if you're lucky enough to have garden space, gardening supplies.

...And now that I look carefully at the photo, you probably do have garden space!

What about some of those narrow slide-out-shelves like they have showcased in kitchens previously? At least that would keep it organized...

I'm picturing galvanized feeding tubs (troughs?) with with wheels added to the bottom with shrubs or trees. They could pulled out to water, etc. Maybe with some small Christmas lights?

Otherwise, a wooden ladder put up horizontally might be a good place to put rakes and the like instead of just on the ground.

I'm thinking something on wheels maybe.

Storage central for all the outdoor tools (and if you have weatherproof containers - anything not temperature sensitive).

It's so narrow and deep, I don't think anything else is practical. But just getting the outdoor stuff organized and prettified (coordinating containers) and so forth would help it at least not be an eyesore!

Use a couple carts (with several shelves), to wheel in and out of the narrow alley.

outdoor curtain.

I'd build a hinged screen that can serve as a trellis in the front and that hides all the junk in the back. You could attach some sort of planter in the front, and let the vines crawl up.

Release everything you consider rubbish. Use the space as a tool shed for larger, non-rusting things like wheel barrows, yard trash cans, large empty pots, large bags of potting material, and gardening seating. A lot of those things can be nested or stacked to maximize the use of the storage space.

Rent it out to a giraffe.

Rolling staircase with storage underneath? Then you can put some pots on the highest stairs and catch that light.

How about a drop-down table-top? You could attach it to the side wall and build shelves on the bottom of it that would contain whatever crafting supplies you would use when the top comes down!

Ditto to Pametto - that's exactly what I had in mind (though a ladder-escape would be awesome, too!)

I'd put a gate in there and keep the trashcans behind it.

I'd put a nice big pot of bamboo on wheels in it, then hide stored garden tools, trash cans, etc. behind it.

http://bicyclestoragesolutions.org/wp-content/uploads/2011/05/bike-storage-rack.jpg

would this fit?

I like Palmetto's idea of hiding it behind a trellis door. You keep it as a storage area then, but also maybe add a narrow potting bench and tool storage. It would be like a secret potting shed.

Don't do the ladder thing. You can go down, but intruders can climb up! On the other hand...if the area is secured, all kinds of Swiss Family Robinson inspirations spring to mind!

The easiest option is to build a solid gate to hide all your tools, etc. and simply use it as storage.
But, I would fill it up wth potted shade plants such as hostas (that need no maintenace at all), and then top it up with mulch or stones - to hide the pots - so it looks like they're in the ground. You would need a 6" high piece of wood to keep the stones/mulch from falling out.

What about some deep shelves at the back, for gardening things, and some skinny shelves along one side. Metal would look good with the brick. You could put some plants that might need shade at the end of each skinny shelf (or along the whole thing), so there's something nice to look at.

Pull-out, full size outdoor shelving mounted on wheels and/or on a suspended rail system (think barn door rail) - sort of like a pull out kitchen pantry. That way you can hide the storage but make good use of the space.

you could hang some ferns from brackets in the wall, or other shade plants.

I like the ladder, but then not so good for storage. Pick one and you can hang pots up either way.

line wih river rocks and install a hose conversion outdoor shower kit for post gardening clean up!

Perfect hanging for outdoor tools, hoses etc! Nice and organized, maybe a pressure treated 2x4 mounted to the wall with zinc hooks down the length of it to hang those easy-reach items like shovels and gardening items??

For a major project, I like bigkoiguy's idea. Sort of like a giant, rustic pocket door. You slide it out and have everything hung on a big door that you need for gardening. For a minor project, leisurely viking has a great idea that will be pretty without too much work.

Make a grotto: water feature, plants, sculpture. Good luck whatever you decide.

I wonder why it's so narrow. You were probably thinking something cheap but if I had that space I would close it off and make it part of the interior room. It's major construction but it looks like it could add over 100 sq ft to your house. If you home value is $250/sq ft then it's like adding $25000. Then you don't have to worry about water collecting back there, cleaning it out, dealing with and unusably tight space. If you do use it for storage then I guarantee in a year or two you are going to forget what is way back there and whatever it is, bike, old grill, is going to get destroyed by the elements.

potpie's comment made me lol.

I would build a platform exactly the size and use non-swivel wheels. On the platform build whatever you need: shelves, bins, stand-up storage, or get creative and build a kitchen. Slide it out when you need it and back in when you don't.

I agree; bigkoiguy's solution is great.

I think there could be room for bigkoiguy's shelving idea, with leisurelyviking's Bamboo-on-wheels infront to mask the shelves... or else, go with potpie's giraffe suggestion which could also double as a means of escape in an emergency... as long as the damn thing doesn't bolt off before you can slide down its neck, of course.

maybe something like this
http://www.materialflow.com/index.cfm?mf=browse.showPart&partClassID=11&PName=6%20Shelf%20Stock%20Trucks

Am I the only one who's really loving the ladder idea?

Yes... ;)