Berachot 6a-b

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See parallel Rif here and here.

[Berachot 6a]
Abba Binyamin says: A person's tefillah is only heard in shul, since it is stated  in Melachim 1 8:28:

כח וּפָנִיתָ אֶל-תְּפִלַּת עַבְדְּךָ, וְאֶל-תְּחִנָּתוֹ--ה אֱלֹהָי: לִשְׁמֹעַ אֶל-הָרִנָּה וְאֶל-הַתְּפִלָּה, אֲשֶׁר עַבְדְּךָ מִתְפַּלֵּל לְפָנֶיךָ הַיּוֹם.

28 Yet have Thou respect unto the prayer of Thy servant, and to his supplication, O LORD my God, to hearken unto the cry {song} and to the prayer which Thy servant prayeth before Thee this day;

in the place of the song {rina}, there shall be My prayer.

[Berachot 6b]

Rav Chelbo cited Rav Huna: Anyone who establishes a fixes place for his prayer, the God of Avraham helps him, and when he dies they say upon him: Woe to the Modest man; Woe to the Pious man. Woe to the one who was a student of our father Avraham. For it states (Bereishit 19:27):

כז וַיַּשְׁכֵּם אַבְרָהָם, בַּבֹּקֶר: אֶל-הַמָּקוֹם--אֲשֶׁר-עָמַד שָׁם, אֶת-פְּנֵי ה.

27 And Abraham got up early in the morning to the place where he had stood before the LORD.

and Amida (standing) only means prayer, as it states in Tehillim 106:30:

ל וַיַּעֲמֹד פִּינְחָס, וַיְפַלֵּל; וַתֵּעָצַר, הַמַּגֵּפָה.

30 Then stood up Phinehas, and wrought judgment and so the plague was stayed.

{except וַיְפַלֵּל is taken to mean "and prayed" rather that "and wrought judgement."}

One should not seek to say that so long as he regularly attends a single shul, it is fine, even if he prays in two different places. For we say in Yerushalmi, perek Tefillat haShachar: Rabbi Tanchum son of Rabbi Chiya said: A person should designate for himself a single place in shul, for it is stated [II Shmuel 15:32]

לב  וַיְהִי דָוִד בָּא עַד-הָרֹאשׁ, אֲשֶׁר-יִשְׁתַּחֲוֶה שָׁם לֵאלֹהִים; וְהִנֵּה לִקְרָאתוֹ, חוּשַׁי הָאַרְכִּי, קָרוּעַ כֻּתָּנְתּוֹ, וַאֲדָמָה עַל-רֹאשׁוֹ.

32 And it came to pass, that when David was come to the top of the ascent, where God was wont to be worshipped, behold, Hushai the Archite came to meet him with his coat rent, and earth upon his head.

Note that it does not day hishtachaveh [implying perfect tense] but rather יִשְׁתַּחֲוֶה ,[implying imperfect/future tense, as well as continuous action].

 Rabbi Chelbo cited Rav Huna: one who leaves a shul should not take large steps.
Abaye said: this was only said regarding leaving a shul, but upon entering, it is a mitzvah, as it states (Hoshea 6:3)

ג וְנֵדְעָה נִרְדְּפָה, לָדַעַת אֶת-ה, כְּשַׁחַר, נָכוֹן מֹצָאוֹ; וְיָבוֹא כַגֶּשֶׁם לָנוּ, כְּמַלְקוֹשׁ יוֹרֶה אָרֶץ.

3 And let us know, eagerly strive to know the LORD, His going forth is sure as the morning; and He shall come unto us as the rain, as the latter rain that watereth the earth.'

{except נִרְדְּפָה can be taken literally as chase.}

Rabbi Zera said: at first, when a saw a member of the rabbinate run to learn on Shabbat I believed that that rabbi was violating the Shabbat. Once I heard that which Rabbi Tanchum cited Rabbi Yehoshua ben Levi, that one should always run to do a mitzvah, even on Shabbat, as it says in Hoshea 11:10

י אַחֲרֵי ה יֵלְכוּ, כְּאַרְיֵה יִשְׁאָג: כִּי-הוּא יִשְׁאַג, וְיֶחֶרְדוּ בָנִים מִיָּם.

10 They shall walk after the LORD, who shall roar like a lion; for He shall roar, and the children shall come trembling from the west.

I also ran.

Rabbi Chelbo cited Rav Huna {we seem to have this as a direct quote on 6b}: Whoever prays at the rear of a shul is called an evildoer, since it says in Tehillim 12:9:

ט סָבִיב, רְשָׁעִים יִתְהַלָּכוּן; כְּרֻם זֻלּוּת, לִבְנֵי אָדָם.

9 The wicked walk on every side, when vileness is exalted among the sons of men.{P}

Abaye said: this is only when he does not face towards the shul, but if he turns to face the shul there is nothing to it.

A certain man prayed at the rear of the shul and did not turn his face to face the shul. An Arab merchant passed by and saw him, and said "Are you turning your back to your master?" He took his sword and lopped off his head.