Persistent Summon Monster and non combat uses

[Conradine]

If an outsider is summoned through a Persistent spell ( 24 hours ), can it be employed for things outside combat?
Like, digging a trench, crafting ( part of ) an item, telling what he knows about any kind of matter, frantically dancing tip-tap ecc.?

[tyckspoon]

..yes? Is there something you've found that makes you think otherwise? You can use normal summon spells for that kind of thing too, as long as the creature you summon is capable of understanding what you want it to do, just the short duration of most Summoning spells makes it difficult to achieve much outside of fighting something.

[sleepyphoenixx]

If an outsider is summoned through a Persistent spell ( 24 hours ), can it be employed for things outside combat?
Like, digging a trench, crafting ( part of ) an item, telling what he knows about any kind of matter, frantically dancing tip-tap ecc.?

In theory yes, but there are no summon spells that are valid targets for Persistent Spell.
That kind of longer-term task is generally what Planar Binding/Ally and similar long-term minionmancy options are for.

Though you could use Summon Marked Homunculus (Dragonmarked) which has a native 1 hour/level duration. So does Summon Devoted Roc, but it's a 9th level domain-only spell.
There's a few other spells with 1 min/level durations too (Summon Dire Hawk (RotW) for example) and of course there's always necromancy, rebuke-commanding, charm/dominate and diplomancy.

Or Body Outside Body. It's Creation, not Summoning, but it's persistable.

[sreservoir]

If you can communicate with the creature, you can direct it not to attack, to attack particular enemies, or to perform other actions.

So, as long as you have a way to communicate with the creature, it's pretty open-ended what you can have it do. Close range is as clearly not persistable as you can get, though.

There's also wall of horse (https://www.d20srd.org/srd/spells/mount.htm) and regal procession (SpC 172), which are so long-duration that it doesn't take much to get them up all day.