Well, I have the straight implementation of libtai as an XS module. Very dull and it will just let you export various sets of functions. All very procedural.
So, now to redefine it into a lovely OO style thing, since OO fits it nicely.
And I must say, Extending and Embedding Perl is lovely. I've never gotten very far using perlxs and perlxstut, but with this book, I have a sensibly functioning module. Woohoo! (Jenness++; Simon++)
Oh, and more tests. Natch. (petdance++)