* I've recently switched to Apple's Keynote software, which makes very tasteful, attractive charts.
* I do all my number-crunching in Excel (including using Excel's very nice "trendline" feature) though usually some initial massaging occurs in Microsoft Access (I haven't found a good Access replacement on OSX, for talking to MySQL (ie, something which helps me write SQL queries and outputs spreadsheets that can go into Excel).
* I use a freeware program called "XL2K" to automatically move my Excel data into Keynote.
* I recently purchase the complete set of design "themes" from Keynote Theme Park and am using their Da Vinci theme as the base for my charts. However, I remove the colored-paper background from the themes, attractive as they are, so that people can more easily print my charts on laser printers.
* When appropriate, I change the colors on the lines to reflect cultural norms, such as using blue lines for male and pink for female.
* The Average and Trend lines are hand drawn based on what Excel is showing me.
* Annoying, when Keynote exports its charts to other formats it does so without drop shadows (perhaps so they print better), so I am screen capturing the Keynote charts (with Command-Shift-4) at their largest screen size, resizing in Photoshop with "magic wand/invert selection/crop/resize-to-450-wide".