Average 1 Bedroom and Studio Rents in Major Cities (x-axis is week number since Feb 15th)

Here is how it was done:

1. PHP script to look through city names (I assume the database exists)

2. SQL statement:

SELECT WEEKOFYEAR( DATE ) AS woy, AVG( rent ) , COUNT( * ) FROM city_counts WHERE city = CITYNAME GROUP BY woy

3. For each city create a simple javascript-friendly string in PHP that looks like this:

{"LA": { label: "LA", data: [[8,1194.9206349206],[9,1261.7650969529]]},

4. Put it all together with Flot (this example) + jQuery.

I know very little (if any) Javascript, but got this up in 15 minutes.