Update: It turns out that LeadPages doesn't support iframes and so the following code unfortunately doesn't work with LeadPages. This code can work with any other providers who allow the iframe tag to be used.
It is possible to use Jumplead in LeadPages, however, our forms are dynamic, smart forms with the ability progressively profile contacts so it's not possible to use static form code.
1) You'll need to create a plain HTML page with the following content.
<!-- INSERT YOUR JUMPLEAD TRACKING CODE HERE -->
<!-- INSERT YOUR JUMPLEAD FORM CODE HERE -->
2) Add in your Jumplead Tracking code & Form Code where the comments indicated, save and upload the file to your server.
3) In LeadPages, add the iframe code below, changing height, width and the src as necessary.
<iframe height="200" width="300" src="/jumplead-form.html" frameborder="0" />
Hope this helps.