bringing = to bring but not "bring". You can say it only while speaking. As I told you before it's perfect as it is.

Shout or shouting? Both are acceptable.
The only thing survivors can do is shout for help.( lwhy "to"is omitted?! That's incorrect here)
From UsingEnglish.
http://www.usingenglish.com/for...-shouting.html

OK,CF.That's enough. I tried your google address you gave, both of them seem to be correct, I mean with or without to.But why don't you accept that we can use a gerund instead of infinitive. For ex: To see is to believe or seeing is believing.
That's all. Nothing I can say to explain it to you.:)

http://www.uop.edu.jo/download/...sh_Grammar.pdf
Read this book in your free time especially "gerund and infinitive" parts.

http://www.uop.edu.jo/download/...sh_Grammar.pdf
I didn't say CF's sentence was incorrect, we can say it while speaking but grammatically it isn't correct.
We can use both gerund and to-infinitive as subject complement but not a bare infinitive. Some convey spoken English to written English. I don't accept them as correct.
Examples: What I wanna do isn't teach you.
All I'm gonna do is meet you at the station.
What's gonna happen now?
Where are TO's in these sentences? Normally we use them in daily conversation. That can't be said that they are correct gramatically.
Some examples of gerund and to-infinitive:
When I was a child what I liked most was to play football.(specific)
When I was a child what I liked most was playing football.(general)
When I was a child what I like most was play football (street English)
No matter whoever said the sentence, even if he is the President or the Prime Minister or a scientist or a writer,if his sentence is not correct gramatically, I never accept it is correct.
I sent you a pdf book, please read it in your free time, especially GERUND and INFINITIVE parts. Take care of yourself.

To what is that sentence correct? I have written some sentences similar to this one, Try to find and read them, I accept your sentence as daily English or street English, why can't you accept my sentence? You have to read to learn English grammatically. Read and see especially GERUND AS SUBJECT COMPLEMENT.That's enough. I don't want to read one more sentence about my sentence.

We sometimes put an infinitive after be when we are explaining what kind of
action we mean.
The only thing I can do is (to) apologize.
What the police did was (to) charge into the crowd.
I read this part and I accept them as a subject complement of a noun clause, why especially sentences beginning " The only thing..." This is a noun clause beginning " the only thing.."
The thing I like most is to play football.
The thing I like most is play football.
The thing I like most is playing football.

Gerund clause as complement after "be"
Jeremy's hobby is inventing computer games.
What I suffer from is not being able to sleep.
An explanation from the Oxford_Guide_to_English_Grammar.pdf file. I hope it helps for you to understand.

I think CK is right. Google agrees:

The only thing I can do is not make any more mistakes.
The only thing I can do, is to drink my own pee.
The only thing I can do is laugh and play it off like its not bothering me but it truly does and they do it to the point where its not funny anymore and its just hurtful.
Maybe the only thing I can do is just take everything he's got.

The only thing I can do is "to" drink my own pee and
The only thing I can do is drink my own piss are correct, I agree with CF.
Can't I say "The only thing I can do is drinking my own pee", if not why and to what? Everybody can write everyting on Google.I don't trust it. You should give more trustable sources.

Why do you insist on the sentences beginning with " the only thing I can do"? It is a noun clause and A lot of similar sentences can be written and can be completed in different ways:
All I could do when I was a child was to play football on the street.
All I can do for you to understand is to give example sentences from the trustable sources.
Nothing you can do can change my mind. etc.
Please study noun clauses, gerunds and infinitives. Especially gerunds so that you can understand my sentences with gerund. I have had enough. Enough is enough.I won't answer next time. Hasta la vista.:)

I agree to CK's sentences:
"Bringing a cup of tea is the only thing I can do" or "Bringing a cup of tea is the only thing I can do right now.".Thank you CK. I gave you some trouble but I agreed with each other at last. For me no difference between " The only thing I can do is bringing a cup of tea" and Bringing a cup of tea is the only thing I can do." When studying at university our Profs had taught us they could be changed each other. And now I teach them as above.

Dear Nero,
CK agreed to a different pattern of my sentence, mentioned above. I agree to that structure:
Bringing a cup of tea is the only thing I can do. I changed the sentence as CK said. Nothing to vote any more. Take care.