As others pointed out its possible. But a big question is whats the point?
The memory management and VM systems in 9x was originally created 8 years ago. It was optimized for PCs that have 32 to 128MB of RAM. Sure you can put a Gig in, but the OS itself will never really use it. The ONLY time all that extra RAM will be used is if you load a application that requires that much RAM. Unless you do some heavy editing with extremely high resolution photos, or do any type of video editing then all of that RAM is just going to sit idle.
The OS will perform at its MAX with 256MB. 512MB may be beneficial if you are playing newer games such as BF1942, UT2k3, etc... Anything over that is just pointless.
If you really want to get a Gig of RAM I suggest getting a OS that will actually make use of it. And won't require myriad of workarounds for it to be functional. Windows 2000 and XP both have modern memory management systems that properly handle and will actually utilize that much RAM.