Vancouver and the Lower Mainland are seeing a pretty impressive proliferation of what are known as community gardens. Vancouver itself has many such gardens, and they are a way for people without the space for a proper garden, or simply without as much space as they would like, to bring their desires to fruition. Some of the gardens have waiting lists, so if you are interested, I suggest contacting the person in charge of the gardens you are interested in ASAP, as planting season in the Lower Mainland began about two weeks ago already.
Last year, the District of North Vancouver (where I live) launched its first community garden. Although I would love to get involved (as would Tim), there is a wait list. If you find yourself in a similar situation, you can go to the City Farmer website, which matches people with excess garden space with people looking to rent or use some. We have contacted a couple people that live near us but unfortunately have received no response, so it looks like another year of balcony gardening for us.
Last year we grew our own lettuce, tomatoes, peppers, herbs (sage, basil, thyme, oregano, marjoram, cilantro, parsley), and even some bok choi. I would definitely encourage anyone to try any of those vegetables and herbs. The tomato plant, which we actually bought almost fully grown, ended up getting a bit rotted and then died, and all of the plants died over the winter (our balcony gets no sun whatsoever during the winter, so this is going to happen every year, I'm sure), but during the summer it was amazing to eat fresh grown salads and herbs. We go through a lot of lettuce at our house because we both eat a salad every day at lunch, and I've always noticed that the lettuce you get from the store is not that fresh looking. If you grow about 12 heads of lettuce, you can just remove the outside leaves each day (plenty for two people) and the lettuce will continue to grow outwards and you will have a constant supply of fresh lettuce.
Tomatoes and peppers are extremely pricey (particularly organic), so they are also a worthwhile plant to have at home. This year, now that I've figured out how to can things, we would really like to grow a massive amount of tomatoes so that we can have a supply of tomato sauce and salsa to last us through the winter. We may end up having to go to a U Pick Farm and get enough that way, as twenty tomatoes only seems to produce about four pint jars of tomato sauce. Either way, I'm looking forward to a productive and delicious summer!