After crying last year at how dry the garden was, and losing all my seedlings, in late 2010, I decided to take a more pro-active stance and finally put in some irrigation piping. This was "2nd hand" piping, just pulled out another section of garden where it had lain unused for years. This limited my ability to decide where the drippers/sprayers are located (as in, they were already in the pipe from the other garden), so I just snaked it through the garden as best was possible. I then bought a $20 battery operated timer from Bunnings, and connected it to the town water tap. The plan is to connect it to the tanks eventually, but we need to put a whole new connection on for that. This has worked pretty well- nearly all the summer seedlings survived (and thrived), and we can now go away for weeks without having to think about how to ensure the garden survives. It's currently set up to just give 'adequate' water, that is, most plants still need a good rain to have a decent growth spurt (corn shot up after a week of night rains) but at least plants aren't dying of thirst in the summer heat.
We are still mulching with leaves, and cardboarding, and I've started to build little palm leaf barriers (poking palm sticks into the soil and threading the longer palms leaves through as type of lattice) along the edges of the mounds. I found that many leaves/cardboard/seaweed was quickly breaking down and leaving exposed sandy edges that lost alot of water along the mound edges. With the palm leaf (and cardboard) barriers, the edges are more protected and the water retention excellent.
We've got butternut and golden nugget pumpkin coming on, corn soon ready for harvesting, capscuim (3 year old) producing crisp tasty fruit, passionfruit doing ok but not fantastic, a self sown tomato producing orange sized tomatoes, silverbeet, parsley, basil, and so much rocket that I am sick of eating it!. There are also in blue lake beans, soy beans, lentils, cowpea, zuchini, cucumber, eggplant & okra - though these are all a month or three away from producing fruit.