This must be old news, since its been on Palmgear since last November, but I thought I'd post it anyway since I hadn't seen it here.

<URL>http://palmgear.com/software/showsoftware.cfm?sid=63078220000708184754&prodID=4906</URL>

This is a compiled Applescript that you can use to set Eudora as the default emailer when you're working in Palm Desktop on your Mac. To get this to work:
1) Put it into the scripts folder in your palm folder
2) Open a contact and open the Other info box. 3) There is a pull-down menu next to the email field. Choose Field Options.
4) You'll see a dialog box where one of the choices in Script. Set this to "Create Eudora PrPrPr...&$quot$;

Now when you click on the icon that normally asks for Claris emailer it will open a new, addressed email in Eudora.

Although it says Eudora Pro, it works fine with my ancient Eudora Light 3.1