no, but if there is a setting that lets you sign back in as the status you signed out as. so if you enable it and sign off as invisible, when you sign back on it will be the same. but from an external standpoint, no.
YES. There is a way. It is not an automated sign in though, it just requires one extra step.
Normally, (and perhaps by default) ichat will automatically log you into your screen name when you open ichat. Of course at this point you will be "available" and are vulnerable to your buddies seeing you are logged in. It seems you want to peek your available buddies without certain people knowing you are online (I don't blame you!) Here is your solution:
What you need to do is this:
Open ichat, go to preferences.
DISABLE the box that says "automatically login when ichat opens".
Now, when you OPEN ichat, you will NOT be signed in to your screen name.
Click on "invisible" in your options of your buddy list.