I like to give my players choices, which is why I have a house rule for allow custom muses if players like. I use a muse template, originally borrowed from Consumerdestroyer on the Eclipse Phase forums with added material by The Alexandrian, that lets my players create just the sort of companion they want. This extends to handy AIs as well, though, which gives me some life-preservers to throw to floundering PCs.
Some areas in particular where players might need help are those times when they wander into the middle of a truly alien society. The formally-harsh culture of the Ultimates, the niche societies of Mercurials, the purposefully-confusing habs of Brinkers… All of these can be startling to players and potentially derail their investigations. Sometimes you want this if it’s the focus of a scenario but when you want to just have some background it can disrupt the flow of the game.
To remedy this, I have a few sample custom muses which are designed as helper AIs for players. I don’t recommend making one of these your default muses but you can keep them as either a backup program (in a ghostrider implant or a device with enough computing power as described on p. 143-145 of Transhuman) or as a temporary muse while you’re in a foreign situation (with your regular muse stored and waiting for you like a minimized Clippy).
The suggestions for Maximizing Your Muse in Transhuman (p. 167-169) are good guidelines for GMs and players alike in creating custom muses. Keep in mind that regular muses know their hosts so well because they’ve grown up with them. A muse that is only used for help will not be able to make suggestions or anticipate their user’s needs as well as a regular one and that may cause more annoyance than usual.
A muse like Mr. Go-Places will suggest restaurants based on mesh reviews, not on the user’s preferences simply because it doesn’t have a great handle on those yet. Cultural guides for other communities or Mercurial niches are more focused on the communities they’re programmed to help with than the users entering them and may come across as cruel or abrasive. Hopefully this is a fun element of your game and not an annoyance so watch out for that…