I'm not going to try to talk you into upgrading since after reading your post, I think that you really, really should invest in an external hard drive and start backing up all of the so called important stuff you have on your Mac.
With a 5 year old machine and all that you have invested into your work - time and money wise, you better think about backing all of that up - before you worry about updating the OS.
I do believe that an upgrade to the OS would ultimately be in your best interest, but first things first.
You are asking the right questions.
As others have said, get an external hd, and make a backup. If all goes bad, you can revert.
When you upgrade an OS, things can go bad. Mostly, they won't, but there's no guarantee.
You should check into whether the version of Photoshop you're running will work with SL. You may need to upgrade Photoshop, as some older versions will not run under SL. Ditto for every other app you're running.
You mentioned that you do not have the means to back everything up, and I get that. However, if you have important data, you should look into finding a way to backing up your data whether you upgrade or not. At some point, your Mac may just not boot up some day. There are online backup solutions such as CrashPlan and Carbonite that will backup everything for a few $$$ per month. The initial backup will take days/weeks depending on how much data you have, but like I said, whether you upgrade or not, any Mac, new or old, can crash and burn without warning.
I just don't have the means to really back everything up, such as an external hard drive
Well your data is considerably more valuable than a $50-$100 USB 2,1 external hard drive you can get at any office or computer store.
If you don't back it up, it's going away pernamently in a very short time as computers and/or hard drives don't last forever.
So that's the first priority
I just might forget about the whole idea of ugrading
I advise you do that as your setup is going bye bye, have to buy new software etc., your going to be spending money.
Also take your computer off the Internet, because it's currently insecure and Apple hasn't released a 10.4 software update in ages.
I advise you wait until 10.8 is released this summer on a new piece of Mac hardware and buy one then, if you can afford it.
Nothing lasts forever, but with your files safely on a new external drive, perhaps you'll get lucky and can use them with a used PC or Mac in the future.
But your present Mac is on it's deathbed, that drive could die at anytime, so at least make the backup.
Okay folks I "get it" about the external drive deal, but even as some have mention here that they aren't "too" expensive, as mentioned I am on a tight fixed income--even if I could get one at around $50 that would be too much--HOWEVER--if by some chance I can save up for one....which one would you recommend??
As I said in my post here, the only way I managed to get my computer five years ago was due to the passing of my mother...and it was not only the computer, but printer, Microtek scanner ( to allow me to digitize my slides and negative to digital format), and computer desk...the whole shabang as I figured I wouldn't get another opportunity to get a computer system with my disability benefits--so, the idea of getting an entirely new computer now would definitely be impossible, that is unless I have an unknown relative that passes on...LOL
@Jeff Kelleher--as you indicated that my version of Photoshop may not be recognized with upgrading to Snow Leopard (or Lion, etc for that fact)--well just suppose I do get a newer version...a newer version might not be then compatible with my scanner?????
as for the CrashPlan or Carbonite on-line back-up--how does that work exactly...does it make duplicate copies of my important data like my documents, photos, etc?
@ds store---the idea of taking my computer off the internet is a no-no--I rely on the net way too much--to supplement my disability benefits I do write articles for different sites and earn money through them...
Anyway--I do hope to sort this all out somehow...going to pick some "brains" with others who have Mac computers
Also it would seem if I do upgrade, I would also have to get a later version of iLife software to replace what I have
Maybe I'll win the lottery...cause it seems whatever I do...I need $$$ for everything
pyewacket wrote: HOWEVER--if by some chance I can save up for one....which one would you recommend??
How big is the drive on your Mac? Need to know that in order to provide any recommendations. If and when you can update to Snow, you will be much more secure on the net. In the meantime, if you run TenFourFox with the Add-on NoScript, using PPC emulation, you will have a much safer browser. The last version of Firefox that ran on Tiger was 3.6 and it's been discontinued for Tiger, even for Intel. But you can still run the latest versions of Firefox with security patches, as TenFourFox. If you keep running as you are, you must be extremely where you use Flash. And make sure Java is disabled.
Taking this off from the About This Mac info...
Model Name: iMac
Model Identifier: iMac5,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache (per processor): 4 MB
Memory: 1 GB
Bus Speed: 667 MHz
Boot ROM Version: IM51.0090.B03
SMC Version: 1.8f2