maybe
DiskExpander can do this. download is one the eab ftp.
it uses the xpk libraries/compressors, which i think should handle zip archives. so you can just test this.
not tested, but the readme says so.
it does compress/uncompress all files on the fly - maybe there is an option just to uncompress.
read the guide or the review above before you are using it
#1) cannot find a xpk ZIP compressor library - gzip bzip2 are on aminet. maybe those are working with zip files. you have to try.
#2)
pploadseg - this will uncompress any PowerPacker packed files on the fly - well, you must convert all, your zips into powerpacker files.
#3) xfdpatch from
xfdmaster archive does the same as pploadseg - but it does not recognize zip archives ...
#4)
xadmaster can handle zip archives - but it has no such loadseg patch
#5) while thinking about it - it my not work with zip archives at all.
bit of work but converting your zips into powerpacker compressed files, is perhaps the best solution.
while it is not about harddrive space, but convenience - this is too much trouble.
but you are free to test what i found above.