The developers behind R-SIM 4 for unlocking  iphone 4 baseband 4.11.08 need another week or so to complete the unlock which is currently at 50%
UPDATE April 5th
Apparently it is not easy to unlock iphone 4 baseband 4.11.08, but at this time we have at least 50% to unlock the iphone 4, so we still need 1 week more or less to improve the program, and please stop sending email to us, just add our facebook page or twitter or keep an eye on our site, we will update the info once it is available,
Also it is not a April joker.