In and of itself that means nothing (it is not like it is an embarrassing part of you). However if I have to try to tie accounts together that are not clearly linked then common interests between them, best if is a somewhat unique combination of them, then it becomes far more useful.
Also I found you linked to
http://www.mediafire.com/download/n1go1efzp36qw77/MOV0004A.avi and claimed you encoded it yourself. I would then run it through something like
http://www.headbands.com/gspot/ to see what it tells me.
Now video like this is not so useful as images and playing with
http://regex.info/exif.cgi (phones like to do things like encode dates, times, GPS locations and more into them, all of which can be read by such things). Sadly facebook and a lot of image boards/hosters sanitise exif data for this reason but again it just takes one slip and you to host it on a normal site. I did scan one of the PNGs from your slideshow but it did not have much of anything in it (though at best I would have found what you saved/captures the image in).
Anyway for those playing along at home
First determine if you are facing someone that wants to hide and is actively doing so (possibly including false info), is cautious but not overly concerned or is clueless/unconcerned. Regardless of your target's position the key is more loose groupings and lots of them rather than trying for absolutes in the initial sweep. Countries, languages and more can inform how you read into things (grammar errors, regional word choices, slang choices and more all help).
Use what you have in front of you (name, location, age, signature, website links)
Use what the site you have info on gives you for more background. All the fancy tools I have covered or are about to cover are invaluable, however some good old likes and interests information is good to have. Moreover it can be the source of the one or two little things that broad automated searches (as I imagine at this point we do not have access to police or even signals intelligence type databases).
If you have something you can narrow down the person with (embed a link to a single pixel image in your post and if the target goes on it with a couple of dozen other people (or you have a time window) then you have quite a bit -- I am sure you all recall those forum signatures that say "you are on IP blah, using [webbrowser] with this operating system...." this is all transmitted to web servers you visit.
https://pipl.com/ is a wonderful site. "Is this username taken" type sites are also useful at times.
http://regex.info/exif.cgi is great for photos (phones do GPS tags and the like).
http://www.headbands.com/gspot/ is a start for video though it will likely have nothing of great interest here.
Good old fashioned search engines with the username and info you might be able to connect to them also works. Do remember you can use a minus sign in a search engine, and things like site: to restrict or remove certain sites from the search.
If you are in America you also have things like
http://www.integrascan.com/ to play with. Be careful with services like this though.
In the UK the electoral roll is posted in a kind of sanitised version online (do a vanity search for yourself).
Do they have a domain? Do a Whois on it, if they have domain privacy find one of those server/IP reports. A lot of people will buy in a multihost package and share it with friends, family and local businesses that just need a site. They often not to use domain privacy and will get you near the same town as them (if the sites themselves do not give contact info).
CVs/resumes, even the sanitised ones, are great.
Do they have a picture of them with their car/motorbike? Most places I go will give me an insurance history or allow me to "text this reg number" and get something similar. Equally quite a few car/bike garages will have a proper hookup into the DVLA (UK) or DOT (US). If they do MOTs then even better and car resale is not much further behind.
From here we take more active steps, however these I have no great desire to cover right now.
P.S. if someone has that youtube series where the guy was guessing people's names/info about them and pretending like they knew them then please share. I appear to have to forgotten to bookmark it.
If you want a nice youtube video though the following is good