Best Candidates for the Spell Stowaway Feat

[Rubik]

I'm looking at epic feats which are actually useful. Sadly, not many of them are. One exception, however, is Spell Stowaway, which allows you to choose a specific spell, and when that spell is cast within 300' by someone within line of sight (all other considerations notwithstanding), you are affected by that spell.

So far, Wish and Miracle look like good contenders, especially with selective immunity to those effects via the helmed horror. Any time someone casts a beneficial Wish or Miracle within 300', you automatically gain the benefit of two of the most powerful spells in the game. The same applies to Reality Revision, with transparency. Time Stop is a definite, as well, so your foes are denied that bit of action economy advantage (not to mention that allies casting it gain double the benefit, since it affects you, too). And Temporal Acceleration, for the exact same reasons as Time Stop.

I'd say that various teleportation options, such as (Greater) Teleport and Plane Shift, would be good contenders, as that would allow you to follow fleeing foes, but without selective immunity, the Spell Stowaway feat activates automatically, and there are times when you don't want to be whisked away from where you are, such as when a friend is leaving your house via teleportation, or an enemy casts Plane Shift on a rock because he knows you're vulnerable.

Anyone have any other suggestions for good spells than what I've got here? Plus, is there any way to extend the effect past 300'?

[Evolved Shrimp]

Well, leShay have the feat natively, and they stow away heal. While that's not entirely without merit - the cleric gets additional mileage from her slots - I find it not really worth spending an epic feat for.

[Jack_Simth]

In addition to Time Stop, the Celerity line is a nice one, because it means when your opponent tries to use an Immediate action to get away... you follow. I'm not aware of any way to change the range, no.

[ben-zayb]

I've used Stowaways for Time Stop, Synchronicity, Temporal Acceleration, Celerity, Heal, Wish/Miracle, Shadow Conjuration/Evocation line, and (Greater) Arcane Fusion before in a PbP Epic PvP before to great effect. Especially effective if you have clones that have any of those as SLAs.

You could make a case for Contingency, for when the feat's "uses this magic" trigger counts.

[Inevitability]

I'm fairly sure being a Dvati could increase the effective 300 ft. area.

[atemu1234]

Celerity is among the best choices, and I'm oft a fan of Time Stop.

[Mr Adventurer]

I've always been confused: does the effect you receive copy the parameters and casting choices of the triggering cast spell?

In other words, if you've got Spell Stowaway (greater teleport) and someone casts that, do you go where they go, or do you just get to GT wherever you want as though you had cast the spell?

[Jack_Simth]

I've always been confused: does the effect you receive copy the parameters and casting choices of the triggering cast spell?

In other words, if you've got Spell Stowaway (greater teleport) and someone casts that, do you go where they go, or do you just get to GT wherever you want as though you had cast the spell?

Well, let's take a look a The Wording (http://www.d20srd.org/srd/epic/feats.htm#spellStowaway)
Choose a spell-like ability you have, or a spell you can cast. You are attuned to the magic you choose. If another spellcaster within 300 feet of you uses this magic, you also immediately gain the magic’s effect as if it had been used on you by the same caster. You must have direct line of effect to the spellcaster in order to gain the benefit of the attuned magic (though you do not have to know the spellcaster is present, and you can be flat-footed). The magic’s duration, effect, and other specifics are determined by its original caster’s level.

Choices of how to use it are not explicitly spelled out, one way or the other. However, DMG, page 6, has an "Adjudicating" section, partly for when you run across something the rules don't cover (2nd column, 2nd full paragraph). The first suggestion for what to do (bulleted list), is:

Look to any similar situation that is covered in a rulebook. Try to extrapolate from what you see presented there and apply it to the current circumstance

The only thing explicitly covered by the feat is stuff related to the caster's level, but includes "other specifics". It seems to me (your mileage may vary) that the closest match, then, is that all decisions are made based on the original caster. So if it's a Greater Teleport, you go wherever the other person does (which may make one of them fail, as the space is already occupied). If it's Time Stop, you use the same d4 roll. If metamagic is applied, you get the same metamagic. And so on.