Can I publish a report from a personal project? During the course of my post-graduation, a friend and I worked on a personal project in pattern recognition. I honestly am not hesitant to admit that although the technique has a decent result on a publicly available dataset, it is not publication worthy in any journal or conference of note (or so I feel), nor do I (my friend is unavailable now) have enough time or background knowledge in the field to keep working on it till it is.

Can it be published as some kind of academic report or something on a site like arxiv or academia.edu or something? I'm interested predominantly because I'm wondering if this online availability would lend more credence to it being mentioned in my cv - as opposed to merely mentioning it and not having any transcript available.

PS: The method was something we came up with. It was not implemented from somewhere else.
There are two different questions in here, one about personal projects and another about whether it's worth publishing a non-peer-review tech report.  

For the first: there is no need for "official" blessing on any scientific work; I've published personal side projects just as happily as projects in my "proper" line of work.  These can end up being quite significant: one of my bits of side-dabbling, published in a minor workshop, kicked off my entire current line of synthetic biology research.

That surprising consequence also leads us toward the answer to the second: significance is where people find it.  If you've put work into something, and written it up in a non-embarrassing way, there's no reason not to put it up online in an archival format, whether arXiv, tech report, or some other low-impact format.  Symposia and workshops can be a lot of fun too, since they often accept things that are interesting but not expected to necessarily be high impact.

If a piece of work is non-embarrassing, what's the worst that can happen if you put it online?  Nobody cites it.  But you never know... your coauthor might end up building something more significant out of it later (happened to one of my side-publications), or it might get noticed by people who happen to be dealing with a similar problem (happened to another of mine), and collect a few citations or even unexpectedly many.

In short: there is never a reason to throw good work in the trash.  Put it online, and let the universe decide whether it's neutral or positive.