h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

It's got a belly liquid-filled,
that by flame's heat was killed.
A grip one-eared your fingers hug.
It's quite easy; it's a ...

(I know this one's really simple, but it was intended for my younger brother. Anyway, I hope someone will guess it soon and add another riddle

You say simple, maybe I'm just an idiot.

Is it a cigarette lighter?

No.

But it is considerably better than what my brother came up with: a slug!

Could it be a cigarette lighter? Please tell me I'm not going completely mad over here! :P

Sorry, but not a lighter.
The two middle lines do not fit that.

Jug!

Somebody else can do the next one as I should be logging out.

If you're going out,
I'll wait for you,
If you're coming out,
Then come with me,
I'll go round you
If you're going in,
My comrades save lives
And some call it a sin.
Useful when nailing
But never a nail,
If I split
I'll turn you pale.

What am I?

It isn't a dog or a shadow, is it? Just checking.
A surveillance camera?

None of those.

No idea. Yet.

No hurry, but you'll kick yourself when you get it.

One clue - a well known UK brand of this is the same as a brand of Australian tape.

If I post an answer do I have to do a riddle?

It was the last two lines of the riddle that gave it away for me

and really, well, I never knew that about Australian tape

Peanut, AFAIK if you feel the urge to post a riddle you can, whether you can answer this one or not.

Although I suspect that you can.

Still stuck? It's a condom.

This one is a less adult theme:

From that which comes within itself,
it builds its table on my shelf.

I don't think I can write a riddle but can give a go at answers, although I am clueless at this point about the last one.

Let it sit for a while and it might come.

"Table" is figurative, not literal, if that helps.

A multiplication table?