First of all: I don't guarantee anything regarding the word "famous"😉
So first question might be: What is a vlogger? A vlogger is short for Video Blogger and if you're familiar with blogs this should explain it all. Basically a video blog is like a normal blog just that it also contains videos. These are distributed by an RSS feed like blogs and tools like iTunes or FireAnt can subscribe to them and automatically download new videos for you (and eventually sync them to a portable media device).
And this article is about what you need to get started with doing videos inside Second Life. I will do this with some links where appropriate as most stuff (for RL video blogs) has been discussed before of course.
I will focus this on video blog aka reporting style stuff as for general Machinima (=videos in virtual worlds or games) you should visit the alt-zoom studio class about it (which is a good idea nevertheless to meet other people in that area and get your questions asked).
So for doing a reportage you might want to have some microphone and you want to look like doing a reportage. For this purpose I created a microphone and some animations. As it's not possible yet to animate your lips to look like speaking in-world I helped me with some animation which moves the head a bit so that it looks like talking. You can get this Vlogger Starter Kit for free at my place.
If you want to have lip-synced speech you might want to check out Crazy Talk for adding this in post-production.
Now you look like doing a reportage but of course you need to shoot video, too🙂
So I am using Fraps for that which is quite easy to use. You might also want to use the client's video capturing method (but this somehow never worked for me). Just make sure you set your compression setting to uncompressed and don't use your desktop as storage as this (as I've heard) is not working (due to some bug). For Mac you might have a try with SnapzPro which does screen capturing.
When shooting video you might also want to disable your UI completely as you don't want to film chat and IMs and menus etc. To do that you need to have your debug menu enabled. You do this by pressing alt-ctrl-d. Then you can switch off your UI completely by pressing alt-ctrl-1. You enable this again with the same keys (but remember them or write them down as you won't have any menu by then!)
Another good idea might be to set yourself to busy mode so you won't be distracted by any IMs which might make noise and so on.
If you're happen to have two computers and an alt you can of course also use one computer to act and another one to record it. For my purpose I find it easier though to use just one as it's less setup and a video blog is for me nothing I want to spend too much time on setup and editing (as IMHO it's more a quick way of getting things out).
My goal is actually to be able to do as much editing in-world already. I am planning to create some tools for that so I can have cuts and effects directly. But as it's not available right now (and you might want to add titles etc. anyway) it's a good idea to use some editing tool. For Mac there's of course iMovie bundled with the computer and for Windows there's the Windows Movie Maker which should do similar things. I also have seen Avid's FreeDV but never used it yet. Of course there are other programs either big or small you can use for it but they might cost money (the small ones not that much though). And mostly every program should give you the possibility to cut long scenes into smaller ones and rearrange them or add transitions here and there as well as titles and credit rolls.
Once you've shot your video you might wanna compress it to some web friendly format and for being used in iTunes you might also want to use Quicktime for it (and for playing it in Second Life as well).
I will link to FreeVLOG for this as this has some updated tutorials and additional tips for you.
Hosting your video
Now that you have your video ready you want to put it somewhere on the web. There are sevaral possibilities to do so. One is of course YouTube. But it has the disadvantage in that it does not supply a quicktime version but only does convert it in Flash. This is unfortunately not viewable in iTunes and Second Life and either not on e.g. a video iPod. You can still upload it there and add it to the Second Life Group for reference.
But for having a video blog it also means that you have a blog and quicktime. So for that there are also several possibilities. One is blip.tv which I personally use. It's free and becomes more and more flexible. It also does convert it to flash but additionally, so your quicktime file is still accessible. It can also provide uploads to your blog and to iTunes automatically. And then there's hipcast which does automatically convert your video (and audio) into various formats for different bandwidths automatically, has iTunes integration and much more (not free though but for a reasonable price).
For the whole process including the blog I again want to point you to FreeVlog as this explains it quite nicely with lots of tutorials.
(and please tell me!)