I Need Opinions....

Man, has my hair gotten long! I go through phases with my hair and I like drastic changes (with the length, not color).....I let it grow, then cut it all off, let it grow, then cut it all off, let it grow, cut it all off, let it grow.....well, you get the point. However, I can't remember a time that I let it get THIS long! My hair is super duper thin so short hair probably suits me better. I'm kinda liking the long hair expect for it getting pulled out by the strap of purse when it's on my shoulder or when it gets caught in my armpit. Other than that, I like my long braided pig tails and messy buns on top of my head. Over the weekend, my sister told me that I should get about 4" cut off. In the midst of contemplating what the next phase of my hair is going to be, I came across this blog today. Those hairstyles were sooo cute and it really gave me an itchin'.....and not the irritating kind. Should I cut it? Reading about her donating her hair really made me want to donate it. I've done it once before and would love to do it again. Suggestions?

Front view....and yes, I'm wearing a Britney Spears t-shirt. Don't hate.