I've seen scripts that do this. But, try these since they are less invasive first:
 
To remove the splash screen from Word 2000 SR-1 or SR-1a, create a new shortcut and add " /q" (<space>/q) to the end of the command line. If you don't have SR-1 or SR-1a, download the service pack at http//office.microsoft.com/downloads/2000/o2ksr1ddl.aspx
 
For Excel 97 & 00 rightclick your Excel shortcut, click Properties & add ' /e' onto the end of the entry in 'target'
 
for Powerpoint 97/2000, use this start command ("Powerpoint.exe" /splash)"C:\Program Files\Microsoft Office\Office\powerpnt.exe" /splash

Cool, those 3 work. Anyone know the rest? (Some not part of the Microsoft Office XP Suite)
 
Outlook XP
Access XP
Frontpage XP
Money 2k2
Streets 2k2
Visual Studio XP

Have three more but you may wish to reconsider using two of them since they involve "hacking" the registry:
 
Access is a kind of workaround - create a 1x1-pixel BMP file and save it in your database directory. Name it as the name of your database's filename, e.g. if your database is named DATABASE.MDB, name your bitmap file DATABASE.BMP. Not the most elegant solution.
 
Outlook Express: Go to HKEY_CURRENT_USER \ Identities
For OE 5 go below this to {ABE2B8A0-C02D-11D3-867B-948FF355BD32} \Software \ Microsoft \ Outlook Express \ 5.0
Add a DWORD NoSplash
Give it a value of 1
 
IE5.0 and higher: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Internet Explorer\Infodelivery\Restrictions
Add a DWORD called NoSplash
Set the value to 1

I don't mind reg entries.
 
*edit* Forgot about Visio 2k2.

For Visio - access the shortcut and in the command line insert:
"C:\Program Files\Microsoft Office\Visio10\Visio.exe" /nologo
or your own path followed by /nologo