Technical and scientific questions which can conceivable by answered by in silico or small-scale, low-cost wetlab experiments:

Technical

Non-standard growth media: Can E. coli grow on "dextro" energy tablets?

Verification of commercial personal-genomics results: Can DNA extraction, PCR and sequencing confirm a SNP result reported by 23andme?

Commercial kit performance: What are the performance properties of various commercial molecular-biology kits?

Can horse meat be reliably detected by a cheap, at-home PCR test?

Do dNTPs show up during gel electrophoresis?

Scientific

pllD: Can activity of the pllD promoter be shown by expression of GFP in a minimal medium?

What organisms live in a home environment? Can culturing, PCR and 16S sequencing be used to identify those organisms?