Craig Hock­en­ber­ry on exact­ly why Apple don’t let devel­op­ers run back­ground apps.

He makes some very inter­est­ing points about the rea­sons why he believes Apple did­n’t include such a fea­ture. He also makes anoth­er excel­lent point about iPhone devel­op­ment:

It takes sev­er­al months of actu­al iPhone devel­op­ment before you even­tu­al­ly real­ize that the iPhone requires a com­plete­ly dif­fer­ent mind­set. Until that hap­pens, you’ll make assump­tions based on desk­top expe­ri­ence, and that in turn will lead to a lot of bad designs

this is one thing that wor­ries me slight­ly. Apple clear­ly spent a lot of mon­ey on research­ing the iPhone and its inter­face as a plat­form, third par­ty devel­op­ers, at least to my knowl­edge, are not able to make use of this which could result in some “inter­est­ing” inter­faces and con­cepts.