Would it be useful for single user single PC or would be overkill?
Can i save time and increase productivity with any version control system?
If answer is yes then which free version control system would be best for me and how I can save time with that?
I work from home and office both. both places I've internet access. I want to access source from both places.
Update:
Can i keep my source on any free hosting? I don't want to keep on MY PC. I need like save and update.
Yes you should use VCS. I'd recommend something low weight like Git if for no other reason that it gives you a log of what you're thinking about at any given time of the week. It's stunning how fast we forget.
It's a lot easier to think about it in the past tense:
Should I have used version control?
Beyond that, subversion works pretty nice and has a lotta different IDE plugins.
If your to the point of considering a VCS, you really should already be using a VCS :)
I would recommend SVN. If you have a fast internet connection at your home, then you could setup a SVN server using svnserve or svnserve/apache. Just get a dynamic DNS service(assuming your IP is dynamic at your home) and then you should always be able to access the source.
Alternative idea: Using file:// repositories and then put the repositories on a flash drive and carry it around with you.
Alternative idea 2: Use a hosting service like Google Code if your code is open source.
I'm basically the sole developer at an ad agency, and I'd be lost without source control. While I don't need it for working on code with multiple devs, it always warms my heart to know I can always do a Revert.
So basically I'll take more risks this way knowing it's all safe and tucked away in SVN ha
Definitely use a VCS, even if it's just running on your local system. I currently have run an SVN repository on my Mac for development work.
Yes you should! I'd recommend Subversion (aka svn) because it's nice and blabla. Tortoisesvn is quite a nice client that integrated in the Windows Explorer.
I find version control very useful even for projects I work on alone, in particular to check in working versions, and if I mess things up, I can always revert to the working version without any hassle.
Of course you should use a version control system. Using a VCS is not only about team development and sharing code, but also about having a history of your source code and being able to go back to an older version at any time (or to maintain older versions while development goes on). You will never want to think how you worked before once you are using one.
Personally, I think subversion is very easy to setup and to use especially when using the subversion client tools such as TortoiseSVN, AnkhSVN, VisualSVN and so on.
If you are looking for a hosted solution, there are lots of questions covering that topic, e.g: http://stackoverflow.com/questions/111292/free-version-control-services
I use git, and here are the things I can do with it that have nothing to do with collaboration:
Have you ever played a game, and you get to a level that's really difficult, so you play it in stages with save points. You get half way through the stage, you make a save point, and then proceed to die 10 times, always going back to the save point instead of all the way back to the start of the level. It's almost cheating!
Or in RPG's, you come to a point where you have to make a decision. Do you like Aeris, or Tifa? Well, make a save point and see what happens both ways!
Git is like that.
The other really nice thing about git is you don't have to set up a damned server like you have to do with SVN or CVS.
The overhead for having version control is pretty low so like the rest of the answers here I'd say it always worth it. Also I'd go with a distributed solution so you're not tied down to a server like you would be with cvs or svn.
A couple of people have suggested git, I use mercurial (actually tortoiseHg so I get the shell integration) which works well for me. As with git you could use just about any hosting because at its most basic all you really need is a file share where you can push out your changesets and then import them in somewhere else.
Lots of IDEs provide integration with source control out of the box, I'm using Netbeans which has decent handling of css, javascript and html. If you're using notepad++ then you'll find it way more powerful (as much as I love notepad++ and have used it for years)
Regarding Online/Free Storage
It's not specifically for VCS online storage, but mozy.com allows you to backup up to 2Gb of current data online for free. What this means is that you can back up 2Gb of your stuff, but it also keeps historical backups for 30 days, -> if you were backing up daily you could conceivably use 60Gb for free.
Once it's set up, its a simple Task/System Tray app and single click to backup whenever you want (as often as you like).
For a VCS like GIT, this would be sufficient, as you could simply include the GIT repository in your list of files to back up.
It may be more difficult to use for a more "centralised" repository like SVN, but still possible - or you could at least just backup your working (but not historical) copy