I've found a few utilities for Windows that allow one to mount a network drive over SSH using SFTP/SCP (WebDrive, SFTPDrive). The chief limitation with these is that 'network drives' can't be mounted in folders or re-shared and are ignored intentionally by most backup solutions (they are not treated as real, local filesystems). For Linux, there's SHFS and LUFS which get the job done with some kernel modules — Linux at least is there already. I haven't found anything for Solaris or Mac yet.
Does anyone know how to overcome the Windows 'network drive' limitations, or have a Solaris solution to complete this puzzle? I'd love nothing more than to be able to export a drive from linux and solaris and mount it into a Windows folder, then turn around and do the same thing from solaris to linux and vice versa. Given the prevalence of SSH, this would be a win for everyone, especially given the security problems of most filesharing solutions when compared to SSH. This is not quite as trivial as it seems, since the mounting mechanisims would necessarily tie into the kernels of each of the operating systems, unless they could cleverly exploit what's already there. Thoughts?