It makes a reasonable functional stim IMO - I've run the gauntlet of 'illegals' (can't be arsed with guessing exactly what my 'speed' actually contains, chemically), tried a bunch of RCs (risk-tastic, and I've not found anything yet that doesn't have some vicious down-side), and keep coming back to good old methylphenidate.
I have seen the extended release (XR, LA, whatever) pills - they are merely more of an irritation to deal with. Even the instant release pills need extraction IMO. MPH isn't really the sort of 'once-a-month let's get high' drug - it's more functional and lends itself to daily use - whether as a wake-up bang, or a pick-me-up to deal with the typical office worker 3pm-fade. As a result, given the cost of the drugs, it makes most sense to maximise both harm-reduction *and* effect.
By harm-reduction, I'm talking about the lung damage that pill fillers can cause, not any aspect of the pharmaceutical itself. My choice of extracted MPH pills reduces harm firstly by starting from pharmaceutical-grade drugs (i.e. blister packed branded Ritalin). Maybe one day I'll get taken down by incredibly detailed fakes with poison in them, but for now I'm assuming that blister-packed Rit contains what it says on the package insert, and the millions of American schoolchildren taking them (which still gets a 'WTF' from me, being English) suggests that the drug isn't a long-term neurotoxin and I won't spend my old age dribbling out of every orifice.
However, snorting MPH works. Snorting a load of talc, various polyethylene glycols, povidone etc. is NOT good for the lungs - however even a completely basic water / coffee filter extraction is 'good enough' to remove the lung-irritant components of most pills.
My method is simple - put the pills in a beaker, pour in hot water, stir until pills dissolved, leave to separate, pour top layer through coffee filter paper into evaporation vessel, add a bit more water, agitate and then pour entire milky mixture into filter. Once the easily-had liquid has filtered through, I then pick up the filter paper cone, fold top edges over etc. and squeeze out as much remaining liquid as I can before the filter paper breaks and white crud ends up in the clear filtrate (doh - you'll learn when to stop after one or two re-filter jobs!).
How you evaporate the filtrate is up to you. Those with lab equipment can apply vacuum to boil off the water at room temperature, I tend to use a close lightbulb and a fan - but don't let the result boil dry and then start to burn - it'll go brown and will taste nasty as well as reduce the effect. Those of you with chemistry experience know all of this, but for those without a traditional chemical education, due to the adulterants present in the filtrate, a 'glass' can form which wastes time turning into usable powder. Seeding crystals by scraping the surface of the 'glassy' liquid when it's down to 'nearly evaporated' will start off the crystallisation step and you'll start getting white clumpy stuff. It's good to attend to the mixture at this point, and keep scraping around so you end up with a dry-ish powder. Heat can be removed then and it'll dry in the air.
Using water as a solvent results in the final mixture containing lactose and MPH. I'm not too bothered about snorting the remaining lactose (it's the burning lactose that gives the brown 'hint' that you're overheating the mixture when evaporating, IIRC) so the alternative (using an EtOH solvent) carries too high a risk-reward ratio. Evaporating volatile, flammable solvents is more dangerous than evaporating water...
With the extended release formulations, one cannot use my normal method - but the above suggestion of crushing the pills / beads (if in capsules) with a pestle and mortar works as a precursor step to the normal extraction. All you need to do is get the water into the matrix of the time-release wax. If grinding the beads smears wax around, then the suggestion of baking soda would work - but you'd end up with baking soda in the final extract. If that's OK for you, it will work.
The main issue with snorting Ritalin regularly is the same as any regular pill-snorter - the talc and other inert substances in pills can cause long-term damage to your lungs. A simple water extraction with no chemistry equipment or knowledge required is all you need. If the evaporation is taking too long, a dash of isopropyl alcohol (2-propanol) towards the end will reduce the solubility of MPH in the solute, but ensure that you heat the resulting crumbly stuff to get rid of any isoprop before insufflating...
It's not particularly cheap or the best buzz, and MPH does have side-effects, but I haven't found anything better as a *functional* stimulant. The filtered extract is even nice and easy on the nose for insufflation - no nasty drip either. If anyone has something better, I'd like to know, but there's a real trade-off between side-effects and general usability with drugs. Ritalin seems to be in that sweet-spot, at least for my neurochemistry.
I'd definitely advise getting the talc out of your pills if you're going to snort regularly, though...