I'll have to try that in PS elements5 and see what the file size is.
Nikon D300, D3s, Nikon 10.5 lens, RingT105N+Footplate+MrotatorTCPs, Giottos MT9261 Tripod, Manfrotto 410 Jr geared head.
If you know the "secret" then everyday is a good day!
Here's my real estate tour workflow. I can shoot a 4000 sq. ft. house in about 45 minutes if there is no one there to bother me. Now, I do use a Canon 5D with a Sigma 8mm fisheye, so I only need 3 bracketed images per scene = 9 images. I shoot RAW.
I download my RAW images to the computer.
I use Canon's Digital Photo Professional - supplied free with my camera - to adjust color balance, then convert to JPEG images.
I then load the images into Photomatix Pro 3 via Batch process. It blends the three 9 images per scene, while I'm working on the still images of the same house.
Once the batch is finished I simply stitch them in Panoweaver 5.0 ending with a 4kx2k image size.
I load the stitched image into an old version of Photoshop CS, do any further brightening, resize to 3000x1500 and use the "Save for Web" feature to end up with an image between 750kb and 1.3mb file size.
All of this takes me about 30 to 45 minutes. I find that's all that is necesary for real estate tours. Especially for what I'm able to charge in my area. My total Tourweaver 4.0 file size is about 6 to 7MB in size and loads fairly quickly with a highspeed connection.
All I can think of is the usual stuff like:
Temporarily flatten image layers (keeping a copy of your original PSD somewhere safe).
Convert image to 8-bit (Photomatix HDR ... 16-bit?).
Convert image to sRGB color space for web.
Reduce image to 72ppi for web.
Close all unnecessary programs that hog RAM (Outlook, Internet Explorer etc.).
Maybe increase PSE5 scratch disk allocation in your preferences (if it has one?).
...and as tturner suggests - try Save for Web again.