You need to install the Gingerbreak APK. Install the app, open it, read the instructions carefully and let it do its thing. When mine was finished, the DX100 shut down and I had to use the reset button (tricky to hit, that thing is!) to bring it back to life. After that, I had root access on my DX100. Once you have that, update SuperUser from the Play store and install the full (=Paid) version of Titanium Backup. This will allow you to "freeze" apps, so that they disappear completely, as far as the OS is concerned, but can be easily re-enabled from within Titanium Backup. But here's the tricky bit: Freeze the wrong service and you might not be able to access TB again to unfreeze. This is where you might brick your DAP if you're not careful ONLY to freeze apps that you are absolutely certain about. Make sure you install another launcher - I prefer AWB to Go Launcher as I find Go to be a little bloated with stuff and gadgets I don't need on my DAP. The launcher is your entire user interface, it's the steering wheel, pedals and gear knob. You'll want to have one.
I assume no responsibility for this. If you break your DX100, it's not my fault.
Right, you have been warned. The apk is here: Http://www.sorensiim.dk/stuff/files/GingerBreak-v1.20.apk
First: Do a full backup in Titanium Backup
Stuff I have frozen and/or uninstalled using TB:
Launcher (Danger, Will Robinson! Make sure to install another launcher first!)
Search 1.1 (does not disable searching in the Music app)
Search Application Provider
Ethernet Settings (Not needed since the DX100 doesn't have a RJ45 connector...)
Google Calendar Sync (I use my phone for calendar stuff)
Pico TTS (Text To Speak service. Useful for GPS navigation. If the device had GPS)
Start screen tips
TTS Service 2.3.1
Animated background chooser
...something labeled in Chinese. The chinese keyboard I assume.
ES File Explorer (Only because I prefer Root Explorer, you might want to keep ES)
That shoddy calendar app Ibasso for some unknown reason saw fit to include.
Two things I just want to add:
1) If the above instructions are not detailed enough for you, you might want to get a friend to help you or avoid rooting your DX100 entirely. I mean no disrespect and I'm sorry if I offend anyone, but if you can't swim then keep your ass out of the pool.
2) A head-fi'er actually asked me if a cracked version of Titanium Backup would work. That's just low. $829 DAP and you couldn't find $5 to support the developer of one of the best Android apps ever made? $cumb@g. Go read this: http://theoatmeal.com/blog/apps