I think it looks a bit painful, but apparently the skin derma roller can bring about a flawless complexion. There have been rumors that it is Angelina Jolie's secret to to her beautiful skin. It is a small hand held device, covered with tiny steel spikes, sharp, but not quite needles. You roll it over your skin, causing trauma to the epidermis and stimulating the repair process, thus boosting collagen production for a coveted youthful glow. The theory is the same behind lasers, which do work miracles. I would know, I swear by laser facials. The derma roller is safe for all skin types. Here are claimed results:

The derma rollers cost between $75 and $85, depending on 'needle' length.  

Stretch marks often occur during puberty when the tissue under the skin is pulled by rapid growth or weight gain, causing a disruption in the normal production of collagen and challenging the skin’s natural ability to stretch. As a result, scars called stretch marks may form, first appearing as reddish or purplish lines that have a different texture than surrounding skin. With time stretch marks turn white and are less noticeable but remain as scars in vulnerable areas like the hips, breasts, buttocks, abdomen, and thighs.
For many women stretch marks also form during pregnancy, for the same reason mentioned, rapid weight gain. Stretch marks are more noticeable in darker skin and there is very little that can be done to eradicate them aside from high powered (and expensive) lasers. Here are some other 'remedies'.

Microdermabrasion can be effective on more manageable stretch marks, by exfoliating the skin with an aluminum oxide spray. Generally, this treatment doesn't pack the punch to eliminate  heavy scarring, but it works brilliantly on lower end cases, while also offering one of the safest methods available for striae (single stretch mark) removal.

Available at med spas or in conjunction with a microdermabrasion treatment, topical creams can be quite successful in smoothing out recently developed stretch marks, minimizing their length and depth. Some of the more popular stretch mark removal brands include StriVectin®, Zenmed® Stretta, and Trilastin®. Below is an image of typical results using a topical cream. The subject is a 22 year old female.

before                                           after 24 days of topical use

These two treatments should be tried first, because lasers are pricey. For dark skinned people and African Americans, lasers may be your only option.

There are two primary types of laser stretch mark removal, laser skin resurfacing and laser skin rejuvenation. In laser skin resurfacing, the outermost layer of the epidermis is removed, encouraging new cell growth and filling in even highly developed stretch marks. Laser skin rejuvenation uses a Cool Touch™ laser to delve beneath the skin and stimulate new collagen production. No skin is removed, so laser skin rejuvenation tends to be a simpler, relatively painless procedure compared to laser skin resurfacing, but it's also typically less effective in removing stubborn stretch marks. In most cases neither laser fully or permanently removed all stretch marks, but laser skin resurfacing does achieve better results.

before                                                       after 11 laser treatments

As you can see, these results are great on dark skin, but the subject had to undergo various treatments.