One of the requirements for the twitter client we are developing for the community is a spellcheck component. What are some of the spellcheck components/systems you have us
I use the TRichView component as my "text editor" in my Delphi application.
It supports many spellcheckers that work with Delphi. You may want to compare the ones that it supports:
http://www.trichview.com/features/spellcheck.html