I have just published a hub about growing baby watermelon on my balcony. This is my first try and I will record its progress through this hub over the whole summer. http://hubpages.com/hub/Baby-Watermelon-In-Contain...
It should be fun and cool. :)
I also plant basil every year. Try not to let the basil to flower and eat the fresh leaves as often as you can. The more you harvest it, the more fresh leaves you'll get.