What do you mean "high and dry"? I use GnuPG in Mail.app on 10.1, and its fantastically easy and effectively presented. Simply install the GPG package, then the GPG-Mail package (a simple bundle for mail.app that adds toolbar buttons and menu options to mail.app to make gpg easy)
If you don't fancy making your keys from the command line, get GPG keys. And for a little extra control over the nitty-gritties, GPGPrefs adds a pref pane, though you're unlikely to need it much.
While I would really be impressed if GPG were fully integrated in Jaguar, I am pretty pleased now with just how easy it is to set-up GPG using these simple, free download tools. I can encrypt messages at the click of a well-designed icon on my mail.app toolbar, and I never had to type any weird commands in.