Schultz at Tokyo Damage Report just posted something you may find useful. In his words

Schultz Wrote:OK, here's something I and my teacher have been working on for the past two years:

A sort of "synonym dictionary" to help us gaijin tell Japanese synonyms apart. What are the differences in nuance, and useage?

And more importantly, when are you supposed to use one and not the other?

I've only glanced at it so far, but I'm definitely going to keep it bookmarked. Find it here

He also recently posted a dictionary of "chiisai tsu words". And finally, for people not familiar with it, he's the author of Kanjidamage, which is pretty similar to Heisig, but free, funnier, and with more swearing. I actually can't think of many people who have come up with and made freely available as many Japanese learning resources as he has, and I kind of wish his work was more well known. So I just thought I'd spread the word a little bit

EDIT: hey this is my 100th post

Interesting and probably worth some usages, but I doubt it's even close to as reliable and correct as a real 類語 dictionary, some of which are already available for free online, for example on dic.yahoo.co.jp.

Tobberoth Wrote:Interesting and probably worth some usages, but I doubt it's even close to as reliable and correct as a real 類語 dictionary, some of which are already available for free online, for example on dic.yahoo.co.jp.

This is true. However I believe this is aimed at learners who are not yet at the point where they feel comfortable or confident using an all-Japanese dictionary, but are still wondering about the difference in nuance/usage between, say, two words whose EDICT entries are basically the same.

手品：　？？？???: ???$$$

Wait, what?