You can embed any public or shareable textivity on your own website, blog etc, just as I have done below.
If you open a text via the text browser, or via a direct hyperlink, or if you upload your own text, you will see a "share" button at the top right of all pages featuring that text. If you click this "share" button, you can copy the embed code into the html of your webpage or blog.
Click on the share button in the embedded content below to see what it looks like. The embedded exercise on this page uses the default dimensions of 500 pixels wide by 600 pixels high, as this seems to work best for blogs such as posterous, but you can change these dimensions and have a play around with what it looks like on your own blog or website. (You can also choose to display the embedded content without the white border).
With posthaven (this blogging platform), the way to embed the exercise is to post via the web, and click the HTML button to edit the html for the post, and simply paste in the embed code.
Why not try it for yourself?