Now I am born on a Cusp. June 21 and that makes me share some attributes from Gemini and Cancer. I always had problems deciding which sign to read cos there are books that put me as a Cancer and there are those that put me as a Gemini. I recently decided to write to Susan Miller to ask for opinions and I even gave her my birthtime GMT and the works to let her decide for me. The answer I got was pretty interesting. Here's a portion of the letter :
"Dear Yee Wei,
Thank you for your letter! I get lots of questions about being born right on the cusp, between two signs. In answer to your question, you are very fortunate, because you take the best of BOTH signs. For personality profiles you probably fit the earlier sign but for forecasts, read the latter of the two (in your case, the forecast for Cancer). It's a long explanation as to why--but it seems to work well this way."
So I have a personality of a Gemini but I will inherit the fate of the Cancer. Mystery solved! :)
Susan Miller's Astrology Site is awesome. Probably the most detailed forecast you can find anywhere. :)