I wonder if anyone can explain this to me? I created a blog to augment my site, having been advised by a lot of people smarter than me that it would help. The search bots have been all over my new blog, even if I've only made three posts so far.

In about a week, I got one search referral, from Windows Live, for the keyword "tramadol" ... which turns out to be some kind of pain pill. Five minutes on Google and I know enough to know it's not like how Google translates "mtn" to "mountain" and sends me lots of traffic from abbreviations.

But there's nothing on my site that could be misunderstood to confuse a photography blog and a sleazy pharmacy. So ... how does a word that's not on any page in a site that's too new to have (m)any links I don't know about, so it's almost certainly not in anchor text in links. Is this really just random?

Could you find your site by doing a search on live for tramadol?
it may also be some kind of spam referrer thing that someone hasn't set up properly

No, but there were 14 m results, and I only looked through page 5. I can't imagine someone looking hundreds of pages deep and clicking my link in the lost serps?

You're saying someone might be testing putting searches with keywords in the referrer field learning to do referral spam? In a way, that would be a relief ... here's what Wikipedia has to say about the stuff - it's nothing I want to be associated with:

Tramadol systems. Tramadol was developed by the (INN) (IPA: [ˈtræməˌdɒl]) is an atypical opioid which is a centrally acting analgesic, used for treating moderate to severe pain. It is a synthetic agent, as a 4-phenyl-piperidine analogue of codeine,[1][2] and appears to have actions on the GABAergic, noradrenergic and serotonergicGerman pharmaceutical companyGrünenthal GmbH and marketed under the trade name Tramal. Grünenthal has also cross licensed the drug to many other pharmaceutical companies that market it under various names, some of which are listed below.
Tramadol is usually marketed as the hydrochloride salt (tramadol hydrochloride) and is available in both injectable (intravenous and/or intramuscular) and oral preparations (e.g. Zydol in UK and Australia, Ultram in U.S., Zytrim in Spain and Canada, and Calmador in Argentina). It is also available in conjunction with paracetamol (acetaminophen) as Ultracet or Tramacet.
Dosages vary depending on the degree of pain experienced by the patient. Tramadol is approximately 10% as potent as morphine, when given by the IV/IM route. Oral doses range from 50–400 mg daily, with up to 600 mg daily when given IV/IM. The 'combination' pills each contain 37.5 mg of tramadol and 325 mg of paracetamol, with the recommended dose being one or two pills every four to six hours.

My site is too new for link-bombing to be a possibility.

mmm tramadol... Maybe you should sell drugs on the side. I hear they making a "killing"

Yeah, I don't judge anyone who uses them, either. I was raised by hippies ... I just don't know how this happens, and don't want it to affect my site's reputation or authority.

It won't.

Several of the sites I have get "refferrals" from MSN or the newer, much slower "Live" search several time a week for these pharmacy type phrases.

It seems to be the latest version of "refer spam", quite what it actually acheives though is a little obscure.

I can't imagine what it could accomplish either ... but I can't imagine how I could legitimately come up high enough in a search for a drug I've never heard of before. I asked a friend who's a doctor, just got back into town from a conference, and she said it's normally prescribed by vets to aging dogs with arthritis, but it's an opiate so of course people abuse it.

So now in MSN or Live's eyes, I'm peddling basset-hound drugs. Or it's some kind of referral spam. #2 sounds less crazy, but it's a close call.

So now in MSN or Live's eyes, I'm peddling basset-hound drugs

Nope, MSN/Live have absolutely no idea you think your site is amongst those results. Because it isn't

The spammers "spoof" the referrer.

I use some ASP code and a (getting larger) database of the referer spam moron sites and give the bot a 403 to think over.

Ah, unfortunately I think I should start doing the same. It's not really a "problem" if it's not actually affecting me on the net, but I'm running on a shared hosting plan, and don't need to use any bandwidth on idiots who aren't going to read the pages they're requesting.

My site is running on an Apache server, but I can accomplish the same thing. I've never gone down this road because the UA is so easy to spoof, and I just have a bad gut feeling about blocking IP addresses and ranges with so many people on DHCP.

I don't block IPs for this, just check the referer value for a matching word or phrase.

That way I can block on a hostname or part of a hostname, imitation search results, affiliate ref code muppets who send 50 requests for several sites in the space of a few minutes and idiots who referer spam their "quality" directories.
So I can block the entire .ro and .ru tlds at one fell swoop should I wish to do so.

For htaccess you can use the

SetEnvIfNoCase Referer to block them

A typical line would be

SetEnvIfNoCase Referer word_or_hostname spamref=yes

then

deny from env=spamref