USB Hacking to MIDI Out 5 Dins Keyboard

I am a totally newbie and keen to learn.

Based on "Collin's Lab USB Hacking with Arduino" video dated November 30th, 2010, I am really inspired to build this device. But some of the parts have discontinued.

#1. The USB host shield has been discontinued - http://www.circuitsathome.com/products-page/arduino-shields/usb-host-shield-for-arduino/. So I have to get the current replacement - USB host shield v2.0 - http://www.circuitsathome.com/products-page/arduino-shields/usb-host-shield-2-0-for-arduino-assembled/. It will also require an Arduino Uno board as the micro controller.

Instead of 2 boards, May I use USBDroid (with USB host built-in) by Freetronics USBDroid (Arduino Uno compatible with onboard Android/USB Host) | Freetronics as this is available locally?

#2. I downloaded the sketch code http://cdn.makezine.com/make/2010/12/LPK25_Host_pde-101203a.zip and paste it to latest Arduino IDE v1.0.5 under OS X and clicked "verify". There was an error on line

EP_RECORD ep_record[ LPK25_NUM_EP ];  //endpoint record structure for the LPK25 controller

the error message said

"EP_RECORD" does not name a type.

Note: In this scenario, I do not have any Arduino board yet (But I'm planning to get one), I have installed Arduino IDE software. Where did I go wrong? See below:

#3 I notice the file extension of latest Arduino v1.0.5 is .ino. The sketch file suffix downloaded above is .pde. Am I downloading the right file? Does Arduino IDE changed user's sketch file extension lately?

Any guidance/explanation would be much appreciated to plan this project properly.

Thank you.

There is a new official USB host shield:-
http://store.arduino.cc/product/A000004
There might be more support with that.

Thank you for your respond, Grumpy_Mike!

As Freetronics USBDroid USBDroid (Arduino Uno compatible with onboard Android/USB Host) | Freetronics is the one I can purchase locally in store, do you think this is sufficient for USB Hacking -> MIDI Out task?

Isn't the compatibility factor based on the code we write?

do you think this is sufficient for USB Hacking -> MIDI Out task?

I think it probably will be, certainly on the hardware level. However, writing such software is difficult and most people relay on some one else writing the interfacing / driver library.
Note that your proposed board is not an Arduino but some one else's take on one, so by definition it can never be 100% compatible.

I checked with the manufacturer and they confirmed the chip used is the same as official USB host by Arduino. By the way, with a help of john [at] viralstudios [dot] net, the script was compiled successfully. So far so good. To be continue...

they confirmed the chip used is the same as official USB host by Arduino.

That means little in terms of compatibly, it is the bare minimum.