On a home page I have nine folders:
Comm
Calendar
Contacts
Corporate Calendar
Email
Gmail
Messanging
Music
Phone
Voice
Voice Dialer
Voice Search
Facebook
Talk
Browser
Easy WiFi
Market
Audio
Shazam
Listen
Music
Pandora
Ringdroid
Slacker
Amazon MP3
Video
Camera
Barcode Scanner
CNET Scan & Shop
Goggles
Key Ring
Scan2PDF Mobile
Gallery
Photoshop
PicSay
YouTube
Qik
Search
Browser
TV-Guide
Amazon MP3
Barcode Scanner
CNET Scan & Shop
Contacts
Droid Dictionary
Maps
Market
Movies
Quickpedia
Voice Search
Where
Yellowbook
YouTube
News
AP Mobile
DailyStrip
Express News
Issuu
Listen
Movies
Quickpedia
SportsTap
The Weather Channel
TV-Guide
Where
YouTube
Droid Dictionary
NubiNews
Games
Abduction!
Backgammon
Barrage Lite
Bebbled
CB Blackjack
Coloroid
Flight Director Lite
Frozen Bubble
Jelix Lite
Jewels
MeteorLite
Mystique Chapter One
Nesoid Lite
Par 72 Golf Lite
Phit Droid Deluxe
Pinball
Radian Lite
Raging Thunder Lite
Slimeball Lite
SNesoid Lite
Solitaire
Speed Forge 3D Lite
Sudoku Free
Vegas Pool Sharks Lite
WaveDefense
Zebra Paint
Zilch Free
Robo Defense
Internet
Maps
Calendar
Contacts
Corporate Calendar
Email
Gmail
Facebook
Browser
Messaging
Talk
YouTube
SportsTap
Market
Utilities
Calculator
Car Home
Notes
Alarm Clock
Bubble
Calculator (a scientific calculator)
Calorie Counter
Compass
Droid Dictionary
DroidLight
Google Sky Map
My Verizon
PdaNet
Scan2PDF Mobile
Shazam
Unit Convertor
Voice Recorder
Voice Dialer
Voice Search
WaveSecure
Market
System
ApkInstaller
DigiClock Settings
DockRunner
Easy WiFi
PdaNet
Settings
WaveSecure
Market
Where's My Droid
That seems to work out just fine for me. Leaves space for the power control widget at the bottom and three blank spots for more folders if necessary (all on my left screen).
My middle screen doesn't have folders. I have the DigiClock widget, Pandora Folder, CalWidget, The Weather Channel Widget, Contacts, Phone, Browser, and Maps apps there.
My right screen is blank.
Still, even with all those apps, I can scan my entire apps drawer with one flick. It's pretty much flick, stab, select.