One trellis with a luffa attemtping to climb it
Anyway, here's some links to get your creative minds thinking:
Pergola ideas no plans with these ones, just awesome pictures
Pergola with planters, plans from the Better Homes & Garden website
Simple pergola plans from Mitre 10 website
Another pergola download PFD document from the Bunnings website
Pitched roof pergola download PFD plans from Magnet Mart website
Pergola construction a pictorial tour from start to finish, of one person's project
Rustic arbour ideas no plans but some great pictures
Entry arbour plans and instructions from Black & Decker website
Square arbour plans from the Better Homes & Garden website
Large trellis which could be used as a stand alone garden feature, or entry way for a house.
Garden trellis download PFD document from the Bunnings website
After all that, you may be wondering what's the difference between a pergola, arbour and trellis? Frankly, I think it's whatever you want to call it. I would consider a trellis anything you can train a plant to grow up, but it can be incorported into the design of an arbour or a pergola too. So what's the difference, LOL?
Have fun looking at all the great pictures and plans - maybe you'll be inspired to look at improving the natural cooling design of simple structures and plants, outside your home.
Just remember you should check with your local building codes (via your shire council) to see if you require planning permission first. If your structure falls under a certain height or floor space you may not need planning permission. If you are intending to attach it to the structure of your house however, you will need planning permission.
If you're afraid of how much it will cost, try using some second hand building materials - not bolts, nails and screws however, as it could compromise the structures integrity. And just think the money you spend on the initial cost, could be saved on less cooling requirements inside the home.
Multi-pronged attacks against the extreme elements, are better than a single option dependant on electricity supply.
EDITED TO ADD: if you use the images links and notice a page about subcriptions pops up. Just use the "back" feature on your browing window, and press the page link again. I noticed it only did this to me, the first time I wanted to click the next image.