I am an experienced programmer, but am fairly new to Linux, having had to use Windows for a long time. What I need now is a driver of some sort to enable me to read Linux partitions from within Windows XP and 98SE. Does such a thing exist, and if so, where can I get it? Thanks for any help anyone is able to give me! :-)

Take a look at:
http://uranus.it.swin.edu.au/~jn/linux/explore2fs.htm

For 2k and XP there is also:
http://uranus.it.swin.edu.au/~jn/linux/ext2ifs.htm

rfstools lets you read ReiserFS partitions from within XP, perhaps 98 as well if you found a proper version. The only downside is that the files are cached to your C:\ partition somewhere before you can transfer them over to another partition like D:\

Another downside is that you can't write to ReiserFS partitions from Windows, but since you can read NTFS and VFat partitions from within Linux, it's more of an inconvenience than anything else for the average home user. For a corporate use, though, it could be a make-or-break problem there...

You can use Total Commander with plagin for Linux. Work good!