Sunrise,
Not sure what exactly you were looking for regarding stimulants and non-ADHD sufferers. I was checking out another topic on PubMed today (pubmed.gov) and figured I would do a quick search on stimulants while I was there.
Using the Clinical Queries link on left I searched for Therapy articles using "Stimulants and Improved cognition". A lot of hits came up. I didn't have time to look at them closely but... Here is a study looking a the effects of stimulants on a physical test and a cognitive function assessment test. Appearently stimulatants can help ya...get up and go AND possibly help you remember where it is you wanted to go...LOL

Not sure what you were really looking for but PubMed's Clinical Queries might give you some leads.

J Am Geriatr Soc. 2008 Apr;56(4):695-700. Epub 2008 Feb 7. Links
Can methylphenidate reduce fall risk in community-living older adults? A double-blind, single-dose cross-over study.

Ben-Itzhak R, Giladi N, Gruendlinger L, Hausdorff JM.
Movement Disorders Unit, Tel-Aviv Sourasky Medical Center, Tel Aviv, Israel.
OBJECTIVES: To test the hypothesis that methylphenidate modifies markers of fall risk in older adults. DESIGN: Randomized, double-blind, placebo-controlled, single-dose cross-over study. SETTING: Outpatient movement disorders clinic. PARTICIPANTS: Twenty-six community-living older adults without dementia (mean age 73.8) with subjective complaints of "memory problems." INTERVENTIONS: The study examined the effects of a single dose of 20 mg of methylphenidate (MPH) on cognitive function and gait. Participants were evaluated before and 2 hours after taking MPH or a placebo in sessions 1 to 2 weeks apart. MEASUREMENTS: The Timed Up and Go and gait variability quantified mobility and fall risk. A computerized neuropsychology battery quantified memory and executive function (EF). RESULTS: Timed Up and Go times, stride time variability, and measures of EF significantly improved in response to MPH but not in response to the placebo. In contrast, MPH did not significantly affect memory or finger tapping abilities. CONCLUSION: In older adults, MPH appears to improve certain aspects of EF, mobility, and gait stability. Although additional studies are required to assess clinical utility and efficacy, the present findings suggest that methylphenidate and other drugs that are designed to enhance attention may have a role as a therapeutic option for reducing fall risk in older adults.