First thanks for looking in,
ok, i jailbroke my iphone 3gs 16g with spirit whilst on 3.1.3. itunes i believe was 9.1 (one before 9.2)
i had this on for several weeks, and then realised ios 4 was due to be released, so, not thinking, and intrigued to see the outcome of ios 4, i restored my iphone and when ios 4 was released i updated to 9.2 itunes, and took the plunge to 4.0.
Not overly impressed i have decided i'd like to put cydia / jailbreak back on my iphone with 4.0 on it, is this possible? i have read about geohot's pwned4life discovery, and had a brief view of the captured video.
Currently my question is, can i re-jailbreak my iphone?
my spec is:
serial ***********
Baseband 05.13.04
Bootloader 6.4
Model MC 131
Unlockable? No
Tethered? Depends if Refurb

I have heard it may be another waiting game, can anyone please advise, the appropriate way to do this, i am uneasy about going back to 3.1.3 or 3.1.2 and don't understand how to go about this even though i have read many posts, - or is it a case of sit tight until the guru's do their magic?
many thanks in anticipation