You can put an alias of the SETI control panel in Startup Items, but while this would launch the application at startup, the window would need to be windowshaded manually. Unless someone can write an applescript that will both launch the control panel, and windowshade right away.
It sounds like you would find it OK for the screen saver to kick in on bootup. The following answer will do that, and with no graphics delay either. But it makes the computer useless for other tasks. I suspect that most people will use only the part to kill the graphics, and leave the startup delay at the default of one minute.
These modifications involve some ResEdit work. Do not attempt them if you are not comfortable with ResEdit. Always keep a backup copy of the file you are messing with in case of mistakes, do not mess with the only copy.
The screen saver can be set to go to a blank screen immediately, but the graphics will still be drawn for a moment. SETI draws the graphics, then checks the blanking delay, so there is no way to avoid the momentary graphics flash.[list=1][*]Open SETI prefs, and set a start delay one minute. Set blanking delay to one minute, close dialog.[*]Quit SETI if it is running, these mods will be overwritten if SETI is running at the time.

[*]Locate the SETI@home Preferences file in /Mac HD/System Folder/Application Support/.[*]Copy out a backup of the SETI@home Preferences file in case of mistakes.[*]Drop the SETI@home Preferences file on
ResEdit.

[*]Open the PiMn resource, then the ID 16000 resource inside PiMn.[*]Select the last set of bytes located at line 000008. This is the blanking delay. If you don't want to mess with the blanking delay, skip to step 9.

[*]Type "0001", that is "zero, zero, zero, one". The cursor will jump around a bit while you are doing this, ignore it. Notes: This is a hex value, in tics. They are 1/60th of a second. Do not use a value of zero, that is the setting to never blank the screen. The pair of bytes immediately before the two in question are higher significant digits for the blanking delay.[*]Next, select the second set of bytes located at line 000010. This is the graphics display time. If you don't want to kill the graphics display time, skip to step 11.

[*]Type "0001", that is "zero, zero, zero, one", same drill.[*]Close the ID 16000 window. The PiMn window should still show a size of 712 bytes.[*]Close both remaining windows. ResEdit will ask for permission to save, allow it.[/list=a]
Your screen saver will now go blank right away, immediately after boot, with only a momentary flash of the graphic display. The momentary graphics flash appears to be a limitation in the application, and there is no way around it. Reboot with extensions off if you wish to use the computer for anything else. Or hold Space while booting, so the Extensions Manager comes up first. Turn off SETI for just that boot.
If you only apply the graphics delay part of the mod, you will have a normal 1-minute kickin delay (or whatever you had set the kick-in to), but nothing but a flash from the graphics when the screen saver kicks in.
If you make any changes in the Preferences dialog, these changes will be overwritten, to "never" in both fields. If you must make changes, you will need to reapply the edit.
Note: Do not use a copy of this modified prefs file with the OS X graphical client. The resources are different lengths.
This modification is one of mine, and is part of the comprehensive SETI/RC5 FAQ - tips - tricks that we are compiling. If anyone wants to kick in some more interesting stuff, just email to
sjaffa@mac.com and
reader50@mac.com .
[ 09-07-2001: Message edited by: reader50 ]