Although Notes is much much better about restarting after a crash there are still times when it hangs. A good example for me is when you open the developer help with the script debugger on.
People used to use products like KillNotes.exe to restart Notes but since version 6 (?) you can use the NSD option with the -kill parameter. I have this set up as a short cut in my menu bar using the following syntax
“C:Program FilesIBMLotusNotesnsd.exe” -kill
Click on the shortcut and Notes is taken down and you can restart notes – with the Notes 8 eclipse client you will probably need to close the large java error pop up