Outdoor bike storage?

[CyclaSutra]

My commuter and kid carrier stay out all summer.
I know rain is terrible for bikes, but I'd like to have my road and mtn bike more accessible to me than stored in our storage unit.

I'd like a storage solution for my yard that's a little more attractive than a tarp.
Has anyone bought a Bike Cave? (http://www.bikemania.biz/Bike_Cave_Outdoor_Bike_Storage_System_p/tt_bikecave.htm)

I hate to spend the $90, but it's probably worth it to the wear on the bikes a summer's worth of thunderstorms could cause.

[Cataboo]

http://www.costco.com/Browse/Product.aspx?Prodid=11530698&search=shelter&Mo=14&cm_re=1_en-_-Top_Left_Nav-_-Top_search&lang=en-US&Nr=P_CatalogName:BC&Sp=S&N=5000043&whse=BC&Dx=mode+matchallpartial&Ntk=Text_Search&Dr=P_CatalogName:BC&Ne=4000000&D=shelter&Ntt=shelter&No=7&Ntx=mode+matchallpartial&Nty=1&topnav=&s=1

Costco has these for about $37 in store.

They are for the most part waterproof, they pop up quickly. The tarp portion at the front folds forward and you can use it as a "door", it closes with toggles & elastic.

IT does let in some water around those windows - but it generally just falls onto the ground of the tarp direclty under it. So you may find the bikes in a small pool of water at the bottom. But it doesn't quite matter if the tires get wet

The fabric of the shelter is waterproof. I've carried mine car/kayak camping a few times and it's done fine.

I've used it as a shelter for my kite buggy:
https://lh5.googleusercontent.com/_WfCe0A3iU1c/TaP8AZaQcQI/AAAAAAAAfaQ/gwTZW6l3sB4/s800/CAT_7270.jpg

When it's closed up, it's like this:

https://lh6.googleusercontent.com/_WfCe0A3iU1c/TaP7zspsK1I/AAAAAAAAfaQ/y-hbhoO7rbg/s800/CAT_7292.jpg

It's not as elegant as the bike cave, but it's cheaper and will work for your purposes.

[Cataboo]

So around the front you do get some moisture:
https://lh6.googleusercontent.com/_WfCe0A3iU1c/TaP71vbcbeI/AAAAAAAAfaQ/kVeRoTPowiY/s800/CAT_7295.jpg

The windows open & close like this:
https://lh3.googleusercontent.com/_WfCe0A3iU1c/TaP8BcB-9YI/AAAAAAAAfaQ/Z_v4NrUtQ1Q/s720/IMGP7123.JPG

So if you got fabric glue and just glued the window flap closed & then put some seam sealer on it, I think it'd be fine.