Hi Marz-
Welcome to the Board! I have also just recently joined, and have found it to be extremely informative and friendly. There are a bunch of great people here, all willing to help.
There are a plethora of dive shops in and around Waikiki (and the rest of the island) that offer OW certification. Most in town offer pick up at your hotel and transport to the various dive/class locations. However, just being recently certified myself, I don't have any personal knowledge of them, just some of what I've heard.
The shops around here offer certification classes usually either in a very short period of time (crammed into a weekend) or over a 1 or 2 week period. If you were going to get certified here, I guess how you did it would also depend on the length of your stay.
The dive shop I got my certification through was Hawaii Sea Adventures. They aren't located in Waikiki, they are in Pearl City, which is about 20 minutes from downtown headed toward the North Shore. They are more of a local/neighborhood shop than one that caters to tourists, if that is a factor you are considering. I can't say enough good things about my instructor; he was very knowledgable, friendly and patient. I LOVED my dive experience through him and now am a certified scubaholic.
Actually, the entire shop is a bunch of good people. While my instructor is both a PADI and SDI instructor, Hawaii Sea Adventures offers the OW cert through SDI only, so if you were set on PADI, that shop wouldn't work for you. They do offer the PADI AOW course, though.
Anyway, I wasn't trying to write a book.
If you needed any more information or I can assist you in any way, drop me a line at
che3par@yahoo.com.
Happy diving!