There are a number of ways to create a pdf file by using open source software. For example, openoffice can export their document files into PDF. But How's about others file type? For example, how can I export a web page into PDF?
I found the best way is getting a PDF Printer driver. I just need to open the file and print it into a PDF Printer. Then it will "print" into a pdf file. I am using PDFCreator to do this task. It is free and opensource.

This week, my friend brought her computer to see me. Her computer can load up a Windows starting screen for a few seconds and it got a blue screen with an error message, "Unbootable Boot Volume". That doesn't seem like a hardware failure, because it can load the start up screen. I found a Windows Vista Setup DVD. I loaded it up. After the first screen which asks me to choose the language, there is a screen with the option for Recovery Console. Then I selected it this one. After that, I chose the Command Prompt. Then I typed "chkdsk C:/r". Then "Waiting.....". After an hour, it scanned the disk and repaired the files damaged. I removed the DVD and rebooted it. It works again!
Reference:
Windows Support

Yesterday, I connected my A500 to my computer. I can do some debug works in this tablet. That is not Plug and Play. You have to download the USB driver in acer. Please select tablet-> Iconia TAB-> A500. After you installed the driver, then the tablet is set to enable for debug and plug-in the tablet via USB. That will works fine!

I have upgraded my Iconia A500 to Android 3.2, I have plugged it with USB Network Card again. That is still not working!!! I think even the OS is upgraded, it won't work! I believe USB Network Card cannot use with an Android Tablet, that is not a recommended way from Google.

I know there are a number of software can generate HDR photo. But most of them are not free. I am a fan of opensource. Thus, I am keen to find whether we can use any opensource tools to generate HDR photo. Finally, I found a tutorial about this. This tutorial shows how to GIMP and its plug-ins generate a HDR-like photo.
This is my final "product":

It looks much better than before, this is a more artistic photo!

Although that is not 100% true HDR, but it looks very very close to a HDR photo.