Are these spam links with my domain in them?

I've been seeing traffic with similar URLs showing up in analytics reports, and every now and then I see them pop up on Twitter, but for the life of me, I haven't been able to figure out what they are trying to do, since when I visit them, they only pull up my website.

For instance, it'll be http://www.sliceofscifi.com/?url=somethinginanothercountry.tld

and I'll see more than a few referrers for it, and today, I saw such a link posted on Twitter that was retweeted 3-4 times.

Anyone have any idea what this might be? Is it spam, or phishing or someone trying to spread malware using my website?