I am w/ back alley and FrankS on this question. When going out for the day (or out on vacation), I take two bodies with three lenses, usually 50/35/28 or 50/35/25 depending on where I'm going and what I'm likely to be shooting. Even so, I rarely change lenses.
FS: Zeiss-ZM Planar 50 plus hood, Pentax MX, Voigtlander Ultron 40/2.0 SLII in Pentax K-mount, Takumar 100/2.8 and 35/3.5 lenses: See my ads in Classifieds
M3, M2, R2A, IIIc, IVSB2, & T, and assorted LTM & M lenses
Minolta XD11, Pentax ME Super, and assorted MD Rokkor and Takumar lenses, Rolleicord III, Rolleicord Vb, Rolleiflex Automat MX-EVS