Are Inlinkz links nofollow?
The quick answer is yes, they are nofollow.
We comply with Google webmaster guidelines, & especially the "link schemes" part, which may be relevant for link parties.
Regarding people that link to parties, outgoing links from the InLinkz widgets, are nofollow and there is not even an option to have them otherwise. This is done to not characterize the links as black hat link building and be penalized by Google.
So, as an InLinkz host, you will not pass pagerank to your readers (and you shouldn't as Google would get pissed off) but you still register as your readers' click source - which makes them link up again in the future as they can see where the extra traffic comes from.
On the other hand, an InLinkz linkup can help you build your incoming links by requiring backlinks to your website. Through the required backlinks feature of InLinkz, you can require from your readers to add a direct html link that points from their site to yours, which as you already know is most beneficial to your exposure.
Keep in mind that you need to provide a button or link to your readers yourself if you want this to be done properly. In any other case, readers will be free to construct whatever they want (which is not always the best for you). If you have a high-ranked blog, you would probably want to provide them with a button with a nofollow attribute set to its <a> tag.
As a rule of thumb, do require a backlink so your entrants' readers can also visit your blog but provide yourself a button or link for them to put in their blogs, that has the rel=nofollow attribute set so you stay google-compliant.
And of course the usual benefits apply: increased traffic and social exposure which creates even more traffic & loyal readers.
We are constantly watching google's guidelines, which are indeed targeted on a better web, and do our best to make the InLinkz widgets support this by connecting people & sharing talent, while complying with those guidelines so our users can benefit as much as possible from using them.
Script codes leading to InLinkz pages (e.g. the wordpress.com code) are also set with a nofollow attribute.
See the code breakdown of an InLinkz link (the nofollow attribute is noted).