I have a working Sony 8mm video camera with about 20 or more tapes which I'd like to transfer myself to DVD or other format (as taking it in is very costly). I understand they transfer in real time but that's ok. I also have an older IBM Thinkpad T42 with XP Prof Service Pack 3.
I am afraid your IBM Thinkpad will not be suitable to do the job as to convert 8mm tapes you actually need a video capture card and appropriate software. If you had a desktop you could have installed the card and software, both will get you to spend the doh. Besides the Thinkpad is essentially a business machine and would be extremely slow for videos even if it had the facility.
The best option that I can suggest to you is to buy a standalone DVD recorder and transfer all the videos to that, it is a very simple setup to be honest. This will also ensure good quality transfer. I am sure that the videos that you need to transfer are important to you, whatever you decide to do you will have to invest a bit to get the results. Of course getting it done professionally is the best option but also the most expensive one.
You can do a search for stand alone DVD recorders and buy one that suits your budget.
Here is a list of such recorders
http://dvr.about.com/od/dvdrecorders/tp/tp5.htm