The above should do for GB/GBC. If you actually mean GBA as the section would imply then you have a few more options, you are a few years late to the party (though it is still going strong) so your options are a bit more limited than they might have been back when.
If you have a DS and DS slot flash cart then you have some options there (
http://filetrip.net/nds-downloads/applications/download-gba-backup-tool-0-21-f3228.html being the better option). Speaking of flash carts if you have one of those then you can always just grabs saves from its memory card.
I have not really seen anything too useful in the commercial world (as in datel/action replay type companies) for this sort of thing -- there were save backup tools for things but they were less concerned with getting things onto the PC.
In the old GBA flash cart worlds there were so called linkers/cradles that many flash carts used. Good luck finding one of these, not to mention you will probably need to find a XP machine or fiddle with a virtual machine to have it work.
If you know your way around with a soldering iron then you have a few more options
http://reinerziegler.de/GBA/gba.htm#cart reader ,
http://hackaday.com/tag/gba/ and possibly some of the multiboot cable stuff if you are not on a DS (
http://problemkaputt.de/gbatek.htm#auxxboopctogbamultibootcable ) should do well.
Do also note the only saves you should be able to lose on game carts are very early SRAM saves (not many have a battery and will instead use flash, a type of memory called FeRAM or EEPROM, all of which are non volatile, not to mention of those with massive quests and whatnot they tend to use flash memory as it can store the most), or anything you might lose to corruption which is not unheard of for several games. Corruption dodging, save injection/hacking and the ability to use things with an emulator (which can also fake the presence of another GBA if you need to do things with link cables) are more than enough to justify this though.
Sort version is get a DS and a basic DS slot flash cart for it, I would suggest a slightly better flash cart if you actually want to play DS games with it but if you just want to run the save/game dumping tool then most things you find will probably work. Personally I quite like the DS form factor for GBA but others seem to like the original or SP form factor more.