There are a lot of little annoyances associated with using the japanese langage IME.

The biggest one that I run into, is I constantly start typing in the wrong language, and then I have to undo everything, change language, and restart. I guess I could probably set up a key to do a conversion or something, which would save me from having to erase and start over. But anyways, I've been thinking about ways to make everything better.

On Japanese keyboards, they have dedicated keys for changing input mode and converting and stuff. I've never used a Japanese keyboard though, so I don't know exactly how all those work. I'm thinking I will explore trying to get a similar setup though. I've noticed that I have several keys that I don't really use, such as Right Alt, and Right Ctrl.
I also wonder if there might be some way to toggle between English and Hiragana with the Caps lock key. Caps lock has to be the most useless key ever, and this would finally give it a purpose.

Anyways, I want to hear from anyone who thinks they have a really good IME setup. How do you have yours configured, and what do you like about it?

I don't know if you've seen this topic:
http://forum.koohii.com/showthread.php?tid=6232

Well since I've already made a thread here, I thought I would post that I have found solutions to some of my problems.

I wanted to remap some of the keys on my keyboard so that they could perform some useful IME functions.

I used a program called sharpkeys to achieve this.
http://sharpkeys.codeplex.com/

I have remapped my caps lock, right alt, and right ctrl keys to function keys F13-F15.
Then within the ime settings, I was able to map those keys to the functions that I wanted.

I treat my caps lock key as a hankaku/zenkaku key, which lets you turn the ime on and off. Its much easier than having to stretch for alt+~.
I use right alt as a henkan (convert) key. If you use the microsoft IME, it lets you reconvert kanji that you have already typed. I can't seem to get this to work with the google ime though. I can also turn the ime on with this key.
Finally I use the right ctrl key as a hiragana key, and shift+right ctrl as a katakana key.

I have that problem too, my friends get english sentences written in Japanese occasionally
祖染めティんgぃ毛てぃｓ << so something like this because i forget to change language.
Japanese keyboards do have a little toggle button, but then they are like childrens keyboards and my hands just devour them and I can't type worth a damn. It takes me twice as long to type anything in a japanese keyboard due to all the redoing i have to make because of the size difference.