SCT just released their new X-Cal 2 Flasher/Datalogger. It adds several new features and is super easy to use, its USB so it can easily be updated over the internet. Flashers work by plugging into the diagnostic port under the dash and reprogramming the stock computer, this takes about a minute to do, then you can unplug the flasher, this is much easier and more flexible than the traditional chip. The Xcal2 reads and clears codes like many of the products already out there. But its also a high speed OBD2 datalogger that works on 94-05 OBD2 Fords. The SCT dealer that you buy it from will custom program it for your car.
The Xcal2 also has 4 aux inputs built in, so you can plug your wideband into it, then datalog and graph everything with the free SCT Live Link software on your laptop. Which is perfect for the low cost LC-1 wideband that www.innovatemotorsports.com
The LC-1 is a WBO2 sensor and controller only, no display, no internal logging (like the LM-1 has) so its very inexpensive, about $200 bucks.
On my car I will use the aux inputs for logging boost and EGTs. I will probably have a setup with dual widebands too (since the LC-1s are so cheap), one in each bank.
Now with a high speed OBD2 datalogger and wideband you are almost tuning. For 95% of people a mailorder tune will be fine, but highly modified NA and blower/turbo cars will require some tuning...
You can use SCT's free PC based Extreme Tune software to make small changes, this is good for an NA car. At some point in the future there will be a free over the internet firmware upgrade for the Xcal2, which will allow those Extreme Tune type changes to be made right on the Xcal2 handheld unit (with the LCD screen and buttons).
Now if you've got a blower/turbo car you are going to need more extensive tuning. You can go with an SCT dealer who will tune the car over the net for you, once you email them OBD2 and A/F data. You can get a dynotune at your local SCT dealer. Or you can tune the car yourself with the Pro-Racer package. The PRP is basically SCT dealer software for the home user (its only for one car), not easy, but very powerful.
If you don't have a local dynotuner that you trust then a remote tune with the Xcal2 and LC-1 is really the only way to go, at about $650 it won't break the bank either (just think what a new motor costs). You CAN'T just trust a mailorder chip, you have to get data and verify the Air/Fuel ratio is safe. There are so many variables that can come into play. Just getting dyno runs with a/f is not really the answer either, there is not enough data there to tune a car, you need additional OBD2 and MAF datalogs, to accompany the A/F data.
The only downside is that for now you need a laptop to datalog with the X-cal2. I have tried a Dell PII 366mhz and it works decent...but 500mhz+ would be better. At some time in the future there will be a free firmware update so the Xcal2 displays OBD2 data live on the screen and stores it interally for later upload to a PC, then a laptop will no longer be required.
X-cal2 in my car: