My vocabulary consists of about 100 words in total (and that includes not-quite-words such as “uh“ and “eh“ and several not-so-good but very multi-purpose words). It's definitely pretty limited and has never been one of my strong points. As a result of this weakness, having quick access to a dictionary has always helped me out quite a bit.
A few years back, I decided to write a quick app to provide me with immediate access to a dictionary and it's been running on my machines ever since. I originally wrote it in C++ in straight Win32 but also wrote a C# version as soon as C# and the framework were capable of doing it.
If it sounds like it would be useful to you, feel free to download it. I just uploaded the binary and C# source and made it available to all on this page. I've also included a link to the old Win32 version which provides the same functionality but is a bit more efficient when it comes to working set, etc. I can't find the source to that version though.
You can find both versions of Wordy and more info on how it works here.