I'd never multi-class a bard. Pure power-wise, particularly in 3.5 when the bard song ramps up so nicely, pure bard will almost always be a better fighter than a fighter/bard multiclass (with the better song and more defensive spells). Maybe 1 level of fighter for a feat (if you MUST) or weapon proficiency -- not more. Delaying spells stinks. A straight bard gets new spells at levels when they are still "pretty good" for the level. Delaying spell acquisition makes bards get, for example, 2nd and 3rd level spells a few levels beyond when they are "neat" or "powerful" effects (just in general). My opinion.
Bards can still make excellent archers; their song stacks with arrow damage, and they have great buffing spells. It's not as sweet as 3.0, granted, but if your party needs an archer, pick a Bard over the fighter-based version just for greater flexibility.
Too much multi-classing robs the bard of its one great power: spellcasting in light armor. Spells are powerful in D&D. The difference between a Bard20 and, say, a Bard14/fighter4/rogue2 is going to be significant on the spell-slinging side.