Acorn Cryotech, a Toronto startup, does this. They store cells from hair follicles, but I think they're still in the process of launching, so you can only get your cells collected at their office or at certain events attended by their staff. It's $300 CAD upfront and $16/month (i.e. $192/year) thereafter.

Is this a good idea?

I don't know a ton about longevity research (i.e. I've read the Longevity FAQ, the LRI blog, and a few papers here and there), so I wouldn't give my opinion here too much weight. Reviewing the FAQ linked above, it seems reasonable to believe that:

• a transfusion of blood generated from younger cells would do more good than a transfusion from older cells
• organs generated from younger cells might last longer, because it would take longer for their cells to become senescent

I expect further developments along these lines. I don't know whether we'll discover methods to reverse cellular aging before we develop practical cell-based longevity therapies.

I'm not going to cryopreserve my stem cells any time soon; I'd prefer to spend my money on charity and freezing my gametes. I think someone with a different budget or different values could reasonably reach a different conclusion.

Bioeden.com might be similar to what you are looking for. They only deal with baby teeth though.

Easy and low cost?  No.  Is it a good idea?  If I could afford it, I would do it, and may still...

Regenexx is the pioneer in the area of non-surgical orthopedic medicine, trains skilled physicians in procedures and have published about half the research papers on stem cell therapy.  They can only do same day autologous procedures in the USA, but at their Cayman location they can expand and store stem cells for future use.  Many professional athletes do this.